| Message ID | 1454603903-15967-3-git-send-email-sudipm.mukherjee@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 04 Feb 2016 17:38:23 +0100, Sudip Mukherjee wrote: > > Modify portman driver to use the new parallel port device model. > The advantage of using the device model is that the device gets binded > to the hardware, we get the feature of hotplug, we can bind/unbind > the driver at runtime. > The only change is in the way the driver gets registered with the > parallel port subsystem and so as a result there is no user visible > change or any chance of regression. > > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > --- > > v3: changed commit message > v2: > 1. pardev_cb is initialized while declaring, thus removing the use of > memset. > 2. used pdev->id. > 3. v1 did not have the parport probe callback, but > we will need the probe callback for binding as the name of the driver > and the name of the device is different. > 4. in v1 I missed modifying snd_portman_probe_port(). > > sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > 1 file changed, 39 insertions(+), 14 deletions(-) > > diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > index 172685d..a22f56c 100644 > --- a/sound/drivers/portman2x4.c > +++ b/sound/drivers/portman2x4.c > @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > { > struct pardevice *pardev; > int res; > - > - pardev = parport_register_device(p, DRIVER_NAME, > - NULL, NULL, NULL, > - 0, NULL); > + struct pardev_cb pdev_cb = { > + .preempt = NULL, > + .wakeup = NULL, > + .private = NULL, > + .irq_func = NULL, > + .flags = 0, > + }; > + > + /* > + * Specify the device number as SNDRV_CARDS + 1 so that the > + * device id alloted to this temporary device will never clash > + * with an actual device already registered. > + */ > + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > + SNDRV_CARDS + 1); Hmm, doesn't this result in a device name like "xxx.33" ? Also, what if multiple portman devices are registered? I suppose rather it should be passing dev variable from snd_portman_probe()? thanks, Takashi
On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > On Thu, 04 Feb 2016 17:38:23 +0100, > Sudip Mukherjee wrote: > > > > Modify portman driver to use the new parallel port device model. > > The advantage of using the device model is that the device gets binded > > to the hardware, we get the feature of hotplug, we can bind/unbind > > the driver at runtime. > > The only change is in the way the driver gets registered with the > > parallel port subsystem and so as a result there is no user visible > > change or any chance of regression. > > > > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > > --- > > > > v3: changed commit message > > v2: > > 1. pardev_cb is initialized while declaring, thus removing the use of > > memset. > > 2. used pdev->id. > > 3. v1 did not have the parport probe callback, but > > we will need the probe callback for binding as the name of the driver > > and the name of the device is different. > > 4. in v1 I missed modifying snd_portman_probe_port(). > > > > sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > > 1 file changed, 39 insertions(+), 14 deletions(-) > > > > diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > > index 172685d..a22f56c 100644 > > --- a/sound/drivers/portman2x4.c > > +++ b/sound/drivers/portman2x4.c > > @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > > { > > struct pardevice *pardev; > > int res; > > - > > - pardev = parport_register_device(p, DRIVER_NAME, > > - NULL, NULL, NULL, > > - 0, NULL); > > + struct pardev_cb pdev_cb = { > > + .preempt = NULL, > > + .wakeup = NULL, > > + .private = NULL, > > + .irq_func = NULL, > > + .flags = 0, > > + }; > > + > > + /* > > + * Specify the device number as SNDRV_CARDS + 1 so that the > > + * device id alloted to this temporary device will never clash > > + * with an actual device already registered. > > + */ > > + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > > + SNDRV_CARDS + 1); > > Hmm, doesn't this result in a device name like "xxx.33" ? yes, it will. But this is a temoporary device just to check if the sound card is connected to that particular parallel port or not. After checking this device is immediately unregistered. My idea here was to have a device number which will never clash with another device number. And we can never have a device like "xxx.33", so no conflict. :) > Also, what if multiple portman devices are registered? Even if we have multiple device, this temporary device will be unregistered immediately after checking for the soundcard. So we should not have any problem. > > I suppose rather it should be passing dev variable from > snd_portman_probe()? Yes, we can. Instead of dev we can just pass the pdev->id for the device number. Then we can have the same device number for the temporary device used for probing and also the same number will be used in the actual device if probing succeeds. Whichever way you want. Shall I send the patch to use the same device number or using 33 as the device number will do? regards sudip
On Fri, 05 Feb 2016 07:17:06 +0100, Sudip Mukherjee wrote: > > On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > > On Thu, 04 Feb 2016 17:38:23 +0100, > > Sudip Mukherjee wrote: > > > > > > Modify portman driver to use the new parallel port device model. > > > The advantage of using the device model is that the device gets binded > > > to the hardware, we get the feature of hotplug, we can bind/unbind > > > the driver at runtime. > > > The only change is in the way the driver gets registered with the > > > parallel port subsystem and so as a result there is no user visible > > > change or any chance of regression. > > > > > > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > > > --- > > > > > > v3: changed commit message > > > v2: > > > 1. pardev_cb is initialized while declaring, thus removing the use of > > > memset. > > > 2. used pdev->id. > > > 3. v1 did not have the parport probe callback, but > > > we will need the probe callback for binding as the name of the driver > > > and the name of the device is different. > > > 4. in v1 I missed modifying snd_portman_probe_port(). > > > > > > sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > > > 1 file changed, 39 insertions(+), 14 deletions(-) > > > > > > diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > > > index 172685d..a22f56c 100644 > > > --- a/sound/drivers/portman2x4.c > > > +++ b/sound/drivers/portman2x4.c > > > @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > > > { > > > struct pardevice *pardev; > > > int res; > > > - > > > - pardev = parport_register_device(p, DRIVER_NAME, > > > - NULL, NULL, NULL, > > > - 0, NULL); > > > + struct pardev_cb pdev_cb = { > > > + .preempt = NULL, > > > + .wakeup = NULL, > > > + .private = NULL, > > > + .irq_func = NULL, > > > + .flags = 0, > > > + }; > > > + > > > + /* > > > + * Specify the device number as SNDRV_CARDS + 1 so that the > > > + * device id alloted to this temporary device will never clash > > > + * with an actual device already registered. > > > + */ > > > + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > > > + SNDRV_CARDS + 1); > > > > Hmm, doesn't this result in a device name like "xxx.33" ? > > yes, it will. But this is a temoporary device just to check if the > sound card is connected to that particular parallel port or not. After > checking this device is immediately unregistered. My idea here was to > have a device number which will never clash with another device number. > And we can never have a device like "xxx.33", so no conflict. :) Ah, this is the temporary one. If so, does it make sense to convert this to dev_model one? This means that the device will be notified to udev even though this is a temporary one to be removed immediately. It's what we'd want to avoid. The function serves just as probing the availability of the given port, not really registering anything there. That is, we need to change the registration flow itself if we really want to move dev_model for the whole. thanks, Takashi
On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: > On Fri, 05 Feb 2016 07:17:06 +0100, > Sudip Mukherjee wrote: >> >> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: >>> On Thu, 04 Feb 2016 17:38:23 +0100, >>> Sudip Mukherjee wrote: >>>> >>>> Modify portman driver to use the new parallel port device model. >>>> The advantage of using the device model is that the device gets binded >>>> to the hardware, we get the feature of hotplug, we can bind/unbind >>>> the driver at runtime. >>>> The only change is in the way the driver gets registered with the >>>> parallel port subsystem and so as a result there is no user visible >>>> change or any chance of regression. >>>> >>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> >>>> --- >>>> >>>> v3: changed commit message >>>> v2: >>>> 1. pardev_cb is initialized while declaring, thus removing the use of >>>> memset. >>>> 2. used pdev->id. >>>> 3. v1 did not have the parport probe callback, but >>>> we will need the probe callback for binding as the name of the driver >>>> and the name of the device is different. >>>> 4. in v1 I missed modifying snd_portman_probe_port(). >>>> >>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ >>>> 1 file changed, 39 insertions(+), 14 deletions(-) >>>> >>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c >>>> index 172685d..a22f56c 100644 >>>> --- a/sound/drivers/portman2x4.c >>>> +++ b/sound/drivers/portman2x4.c >>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) >>>> { >>>> struct pardevice *pardev; >>>> int res; >>>> - >>>> - pardev = parport_register_device(p, DRIVER_NAME, >>>> - NULL, NULL, NULL, >>>> - 0, NULL); >>>> + struct pardev_cb pdev_cb = { >>>> + .preempt = NULL, >>>> + .wakeup = NULL, >>>> + .private = NULL, >>>> + .irq_func = NULL, >>>> + .flags = 0, >>>> + }; >>>> + >>>> + /* >>>> + * Specify the device number as SNDRV_CARDS + 1 so that the >>>> + * device id alloted to this temporary device will never clash >>>> + * with an actual device already registered. >>>> + */ >>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, >>>> + SNDRV_CARDS + 1); >>> >>> Hmm, doesn't this result in a device name like "xxx.33" ? >> >> yes, it will. But this is a temoporary device just to check if the >> sound card is connected to that particular parallel port or not. After >> checking this device is immediately unregistered. My idea here was to >> have a device number which will never clash with another device number. >> And we can never have a device like "xxx.33", so no conflict. :) > > Ah, this is the temporary one. If so, does it make sense to convert > this to dev_model one? This means that the device will be notified to > udev even though this is a temporary one to be removed immediately. But since we are registering a device it should ideally follow the dev_model. > It's what we'd want to avoid. The function serves just as probing the > availability of the given port, not really registering anything > there. To my understanding, it is probing for the availability of the port and it is also calling portman_probe() which is initializing hardware handshake lines to midi box and checking if the portman card is connected to that parallel port or not. > > That is, we need to change the registration flow itself if we really > want to move dev_model for the whole. Any hint, how to register then? Without probing (reading and writing to that port) I can not know if that port is having the card and to use the port I need to register a device with that port. Regards Sudip
On Fri, 05 Feb 2016 17:50:51 +0100, Sudip Mukherjee wrote: > > On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: > > On Fri, 05 Feb 2016 07:17:06 +0100, > > Sudip Mukherjee wrote: > >> > >> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > >>> On Thu, 04 Feb 2016 17:38:23 +0100, > >>> Sudip Mukherjee wrote: > >>>> > >>>> Modify portman driver to use the new parallel port device model. > >>>> The advantage of using the device model is that the device gets binded > >>>> to the hardware, we get the feature of hotplug, we can bind/unbind > >>>> the driver at runtime. > >>>> The only change is in the way the driver gets registered with the > >>>> parallel port subsystem and so as a result there is no user visible > >>>> change or any chance of regression. > >>>> > >>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > >>>> --- > >>>> > >>>> v3: changed commit message > >>>> v2: > >>>> 1. pardev_cb is initialized while declaring, thus removing the use of > >>>> memset. > >>>> 2. used pdev->id. > >>>> 3. v1 did not have the parport probe callback, but > >>>> we will need the probe callback for binding as the name of the driver > >>>> and the name of the device is different. > >>>> 4. in v1 I missed modifying snd_portman_probe_port(). > >>>> > >>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > >>>> 1 file changed, 39 insertions(+), 14 deletions(-) > >>>> > >>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > >>>> index 172685d..a22f56c 100644 > >>>> --- a/sound/drivers/portman2x4.c > >>>> +++ b/sound/drivers/portman2x4.c > >>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > >>>> { > >>>> struct pardevice *pardev; > >>>> int res; > >>>> - > >>>> - pardev = parport_register_device(p, DRIVER_NAME, > >>>> - NULL, NULL, NULL, > >>>> - 0, NULL); > >>>> + struct pardev_cb pdev_cb = { > >>>> + .preempt = NULL, > >>>> + .wakeup = NULL, > >>>> + .private = NULL, > >>>> + .irq_func = NULL, > >>>> + .flags = 0, > >>>> + }; > >>>> + > >>>> + /* > >>>> + * Specify the device number as SNDRV_CARDS + 1 so that the > >>>> + * device id alloted to this temporary device will never clash > >>>> + * with an actual device already registered. > >>>> + */ > >>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > >>>> + SNDRV_CARDS + 1); > >>> > >>> Hmm, doesn't this result in a device name like "xxx.33" ? > >> > >> yes, it will. But this is a temoporary device just to check if the > >> sound card is connected to that particular parallel port or not. After > >> checking this device is immediately unregistered. My idea here was to > >> have a device number which will never clash with another device number. > >> And we can never have a device like "xxx.33", so no conflict. :) > > > > Ah, this is the temporary one. If so, does it make sense to convert > > this to dev_model one? This means that the device will be notified to > > udev even though this is a temporary one to be removed immediately. > > But since we are registering a device it should ideally follow the > dev_model. We shouldn't advertise the device that shouldn't be handled by the user-space. The device you're trying to register there is the one that lives only shortly just for probing the address. > > It's what we'd want to avoid. The function serves just as probing the > > availability of the given port, not really registering anything > > there. > > To my understanding, it is probing for the availability of the port and > it is also calling portman_probe() which is initializing hardware > handshake lines to midi box and checking if the portman card is > connected to that parallel port or not. > > > > > That is, we need to change the registration flow itself if we really > > want to move dev_model for the whole. > > Any hint, how to register then? > Without probing (reading and writing to that port) I can not know if > that port is having the card and to use the port I need to register a > device with that port. Just returning the error at probe of the parport device itself instead of doing the probe twice? The current way is racy in anyway. Takashi
On Friday 05 February 2016 10:31 PM, Takashi Iwai wrote: > On Fri, 05 Feb 2016 17:50:51 +0100, > Sudip Mukherjee wrote: >> >> On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: >>> On Fri, 05 Feb 2016 07:17:06 +0100, >>> Sudip Mukherjee wrote: >>>> >>>> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: >>>>> On Thu, 04 Feb 2016 17:38:23 +0100, >>>>> Sudip Mukherjee wrote: >>>>>> >>>>>> Modify portman driver to use the new parallel port device model. >>>>>> The advantage of using the device model is that the device gets binded >>>>>> to the hardware, we get the feature of hotplug, we can bind/unbind >>>>>> the driver at runtime. >>>>>> The only change is in the way the driver gets registered with the >>>>>> parallel port subsystem and so as a result there is no user visible >>>>>> change or any chance of regression. >>>>>> >>>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> >>>>>> --- >>>>>> >>>>>> v3: changed commit message >>>>>> v2: >>>>>> 1. pardev_cb is initialized while declaring, thus removing the use of >>>>>> memset. >>>>>> 2. used pdev->id. >>>>>> 3. v1 did not have the parport probe callback, but >>>>>> we will need the probe callback for binding as the name of the driver >>>>>> and the name of the device is different. >>>>>> 4. in v1 I missed modifying snd_portman_probe_port(). >>>>>> >>>>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ >>>>>> 1 file changed, 39 insertions(+), 14 deletions(-) >>>>>> >>>>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c >>>>>> index 172685d..a22f56c 100644 >>>>>> --- a/sound/drivers/portman2x4.c >>>>>> +++ b/sound/drivers/portman2x4.c >>>>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) >>>>>> { >>>>>> struct pardevice *pardev; >>>>>> int res; >>>>>> - >>>>>> - pardev = parport_register_device(p, DRIVER_NAME, >>>>>> - NULL, NULL, NULL, >>>>>> - 0, NULL); >>>>>> + struct pardev_cb pdev_cb = { >>>>>> + .preempt = NULL, >>>>>> + .wakeup = NULL, >>>>>> + .private = NULL, >>>>>> + .irq_func = NULL, >>>>>> + .flags = 0, >>>>>> + }; >>>>>> + >>>>>> + /* >>>>>> + * Specify the device number as SNDRV_CARDS + 1 so that the >>>>>> + * device id alloted to this temporary device will never clash >>>>>> + * with an actual device already registered. >>>>>> + */ >>>>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, >>>>>> + SNDRV_CARDS + 1); >>>>> >>>>> Hmm, doesn't this result in a device name like "xxx.33" ? >>>> >>>> yes, it will. But this is a temoporary device just to check if the >>>> sound card is connected to that particular parallel port or not. After >>>> checking this device is immediately unregistered. My idea here was to >>>> have a device number which will never clash with another device number. >>>> And we can never have a device like "xxx.33", so no conflict. :) >>> >>> Ah, this is the temporary one. If so, does it make sense to convert >>> this to dev_model one? This means that the device will be notified to >>> udev even though this is a temporary one to be removed immediately. >> >> But since we are registering a device it should ideally follow the >> dev_model. > > We shouldn't advertise the device that shouldn't be handled by the > user-space. The device you're trying to register there is the one > that lives only shortly just for probing the address. > > >>> It's what we'd want to avoid. The function serves just as probing the >>> availability of the given port, not really registering anything >>> there. >> >> To my understanding, it is probing for the availability of the port and >> it is also calling portman_probe() which is initializing hardware >> handshake lines to midi box and checking if the portman card is >> connected to that parallel port or not. >> >>> >>> That is, we need to change the registration flow itself if we really >>> want to move dev_model for the whole. >> >> Any hint, how to register then? >> Without probing (reading and writing to that port) I can not know if >> that port is having the card and to use the port I need to register a >> device with that port. > > Just returning the error at probe of the parport device itself instead > of doing the probe twice? The current way is racy in anyway. Ohhhk.. so we only register once and if we find the card - we continue, we donot find the card then we unregister the device and return error code. Great. I will send you a patch for your review. Regards Sudip
On Fri, 05 Feb 2016 18:01:16 +0100, Takashi Iwai wrote: > > On Fri, 05 Feb 2016 17:50:51 +0100, > Sudip Mukherjee wrote: > > > > On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: > > > On Fri, 05 Feb 2016 07:17:06 +0100, > > > Sudip Mukherjee wrote: > > >> > > >> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > > >>> On Thu, 04 Feb 2016 17:38:23 +0100, > > >>> Sudip Mukherjee wrote: > > >>>> > > >>>> Modify portman driver to use the new parallel port device model. > > >>>> The advantage of using the device model is that the device gets binded > > >>>> to the hardware, we get the feature of hotplug, we can bind/unbind > > >>>> the driver at runtime. > > >>>> The only change is in the way the driver gets registered with the > > >>>> parallel port subsystem and so as a result there is no user visible > > >>>> change or any chance of regression. > > >>>> > > >>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > > >>>> --- > > >>>> > > >>>> v3: changed commit message > > >>>> v2: > > >>>> 1. pardev_cb is initialized while declaring, thus removing the use of > > >>>> memset. > > >>>> 2. used pdev->id. > > >>>> 3. v1 did not have the parport probe callback, but > > >>>> we will need the probe callback for binding as the name of the driver > > >>>> and the name of the device is different. > > >>>> 4. in v1 I missed modifying snd_portman_probe_port(). > > >>>> > > >>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > > >>>> 1 file changed, 39 insertions(+), 14 deletions(-) > > >>>> > > >>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > > >>>> index 172685d..a22f56c 100644 > > >>>> --- a/sound/drivers/portman2x4.c > > >>>> +++ b/sound/drivers/portman2x4.c > > >>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > > >>>> { > > >>>> struct pardevice *pardev; > > >>>> int res; > > >>>> - > > >>>> - pardev = parport_register_device(p, DRIVER_NAME, > > >>>> - NULL, NULL, NULL, > > >>>> - 0, NULL); > > >>>> + struct pardev_cb pdev_cb = { > > >>>> + .preempt = NULL, > > >>>> + .wakeup = NULL, > > >>>> + .private = NULL, > > >>>> + .irq_func = NULL, > > >>>> + .flags = 0, > > >>>> + }; > > >>>> + > > >>>> + /* > > >>>> + * Specify the device number as SNDRV_CARDS + 1 so that the > > >>>> + * device id alloted to this temporary device will never clash > > >>>> + * with an actual device already registered. > > >>>> + */ > > >>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > > >>>> + SNDRV_CARDS + 1); > > >>> > > >>> Hmm, doesn't this result in a device name like "xxx.33" ? > > >> > > >> yes, it will. But this is a temoporary device just to check if the > > >> sound card is connected to that particular parallel port or not. After > > >> checking this device is immediately unregistered. My idea here was to > > >> have a device number which will never clash with another device number. > > >> And we can never have a device like "xxx.33", so no conflict. :) > > > > > > Ah, this is the temporary one. If so, does it make sense to convert > > > this to dev_model one? This means that the device will be notified to > > > udev even though this is a temporary one to be removed immediately. > > > > But since we are registering a device it should ideally follow the > > dev_model. > > We shouldn't advertise the device that shouldn't be handled by the > user-space. The device you're trying to register there is the one > that lives only shortly just for probing the address. > > > > > It's what we'd want to avoid. The function serves just as probing the > > > availability of the given port, not really registering anything > > > there. > > > > To my understanding, it is probing for the availability of the port and > > it is also calling portman_probe() which is initializing hardware > > handshake lines to midi box and checking if the portman card is > > connected to that parallel port or not. > > > > > > > > That is, we need to change the registration flow itself if we really > > > want to move dev_model for the whole. > > > > Any hint, how to register then? > > Without probing (reading and writing to that port) I can not know if > > that port is having the card and to use the port I need to register a > > device with that port. > > Just returning the error at probe of the parport device itself instead > of doing the probe twice? The current way is racy in anyway. ... and the problem with that is, there is no way to check whether your upcoming change works correctly without the hardware. It would be no longer a "cleanup", and it's risky to do that blindly. I appreciate your work, but it doesn't look worthy enough. If we're trying to eliminate the all old-style parport code from the kernel code, OK, it's an ambitious project and we may consider taking a risk of breakage. Is that the case? Takashi
On Friday 05 February 2016 10:36 PM, Takashi Iwai wrote: > On Fri, 05 Feb 2016 18:01:16 +0100, > Takashi Iwai wrote: >> >> On Fri, 05 Feb 2016 17:50:51 +0100, >> Sudip Mukherjee wrote: >>> >>> On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: >>>> On Fri, 05 Feb 2016 07:17:06 +0100, >>>> Sudip Mukherjee wrote: >>>>> >>>>> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: >>>>>> On Thu, 04 Feb 2016 17:38:23 +0100, >>>>>> Sudip Mukherjee wrote: >>>>>>> >>>>>>> Modify portman driver to use the new parallel port device model. >>>>>>> The advantage of using the device model is that the device gets binded >>>>>>> to the hardware, we get the feature of hotplug, we can bind/unbind >>>>>>> the driver at runtime. >>>>>>> The only change is in the way the driver gets registered with the >>>>>>> parallel port subsystem and so as a result there is no user visible >>>>>>> change or any chance of regression. >>>>>>> >>>>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> >>>>>>> --- >>>>>>> >>>>>>> v3: changed commit message >>>>>>> v2: >>>>>>> 1. pardev_cb is initialized while declaring, thus removing the use of >>>>>>> memset. >>>>>>> 2. used pdev->id. >>>>>>> 3. v1 did not have the parport probe callback, but >>>>>>> we will need the probe callback for binding as the name of the driver >>>>>>> and the name of the device is different. >>>>>>> 4. in v1 I missed modifying snd_portman_probe_port(). >>>>>>> >>>>>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ >>>>>>> 1 file changed, 39 insertions(+), 14 deletions(-) >>>>>>> >>>>>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c >>>>>>> index 172685d..a22f56c 100644 >>>>>>> --- a/sound/drivers/portman2x4.c >>>>>>> +++ b/sound/drivers/portman2x4.c >>>>>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) >>>>>>> { >>>>>>> struct pardevice *pardev; >>>>>>> int res; >>>>>>> - >>>>>>> - pardev = parport_register_device(p, DRIVER_NAME, >>>>>>> - NULL, NULL, NULL, >>>>>>> - 0, NULL); >>>>>>> + struct pardev_cb pdev_cb = { >>>>>>> + .preempt = NULL, >>>>>>> + .wakeup = NULL, >>>>>>> + .private = NULL, >>>>>>> + .irq_func = NULL, >>>>>>> + .flags = 0, >>>>>>> + }; >>>>>>> + >>>>>>> + /* >>>>>>> + * Specify the device number as SNDRV_CARDS + 1 so that the >>>>>>> + * device id alloted to this temporary device will never clash >>>>>>> + * with an actual device already registered. >>>>>>> + */ >>>>>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, >>>>>>> + SNDRV_CARDS + 1); >>>>>> >>>>>> Hmm, doesn't this result in a device name like "xxx.33" ? >>>>> >>>>> yes, it will. But this is a temoporary device just to check if the >>>>> sound card is connected to that particular parallel port or not. After >>>>> checking this device is immediately unregistered. My idea here was to >>>>> have a device number which will never clash with another device number. >>>>> And we can never have a device like "xxx.33", so no conflict. :) >>>> >>>> Ah, this is the temporary one. If so, does it make sense to convert >>>> this to dev_model one? This means that the device will be notified to >>>> udev even though this is a temporary one to be removed immediately. >>> >>> But since we are registering a device it should ideally follow the >>> dev_model. >> >> We shouldn't advertise the device that shouldn't be handled by the >> user-space. The device you're trying to register there is the one >> that lives only shortly just for probing the address. >> >> >>>> It's what we'd want to avoid. The function serves just as probing the >>>> availability of the given port, not really registering anything >>>> there. >>> >>> To my understanding, it is probing for the availability of the port and >>> it is also calling portman_probe() which is initializing hardware >>> handshake lines to midi box and checking if the portman card is >>> connected to that parallel port or not. >>> >>>> >>>> That is, we need to change the registration flow itself if we really >>>> want to move dev_model for the whole. >>> >>> Any hint, how to register then? >>> Without probing (reading and writing to that port) I can not know if >>> that port is having the card and to use the port I need to register a >>> device with that port. >> >> Just returning the error at probe of the parport device itself instead >> of doing the probe twice? The current way is racy in anyway. > > ... and the problem with that is, there is no way to check whether > your upcoming change works correctly without the hardware. It would > be no longer a "cleanup", and it's risky to do that blindly. Yes. That is why I try to change the driver with the minimum possible change. > > I appreciate your work, but it doesn't look worthy enough. If we're > trying to eliminate the all old-style parport code from the kernel > code, OK, it's an ambitious project and we may consider taking a risk > of breakage. Is that the case? Yes, the old api is supposed to be removed and we should only have the device model api. I was expecting to remove the old API by 4.7. Is there any way to get the hardware? Regards Sudip
On Fri, 05 Feb 2016 18:21:46 +0100, Sudip Mukherjee wrote: > > On Friday 05 February 2016 10:36 PM, Takashi Iwai wrote: > > On Fri, 05 Feb 2016 18:01:16 +0100, > > Takashi Iwai wrote: > >> > >> On Fri, 05 Feb 2016 17:50:51 +0100, > >> Sudip Mukherjee wrote: > >>> > >>> On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: > >>>> On Fri, 05 Feb 2016 07:17:06 +0100, > >>>> Sudip Mukherjee wrote: > >>>>> > >>>>> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > >>>>>> On Thu, 04 Feb 2016 17:38:23 +0100, > >>>>>> Sudip Mukherjee wrote: > >>>>>>> > >>>>>>> Modify portman driver to use the new parallel port device model. > >>>>>>> The advantage of using the device model is that the device gets binded > >>>>>>> to the hardware, we get the feature of hotplug, we can bind/unbind > >>>>>>> the driver at runtime. > >>>>>>> The only change is in the way the driver gets registered with the > >>>>>>> parallel port subsystem and so as a result there is no user visible > >>>>>>> change or any chance of regression. > >>>>>>> > >>>>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > >>>>>>> --- > >>>>>>> > >>>>>>> v3: changed commit message > >>>>>>> v2: > >>>>>>> 1. pardev_cb is initialized while declaring, thus removing the use of > >>>>>>> memset. > >>>>>>> 2. used pdev->id. > >>>>>>> 3. v1 did not have the parport probe callback, but > >>>>>>> we will need the probe callback for binding as the name of the driver > >>>>>>> and the name of the device is different. > >>>>>>> 4. in v1 I missed modifying snd_portman_probe_port(). > >>>>>>> > >>>>>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > >>>>>>> 1 file changed, 39 insertions(+), 14 deletions(-) > >>>>>>> > >>>>>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > >>>>>>> index 172685d..a22f56c 100644 > >>>>>>> --- a/sound/drivers/portman2x4.c > >>>>>>> +++ b/sound/drivers/portman2x4.c > >>>>>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > >>>>>>> { > >>>>>>> struct pardevice *pardev; > >>>>>>> int res; > >>>>>>> - > >>>>>>> - pardev = parport_register_device(p, DRIVER_NAME, > >>>>>>> - NULL, NULL, NULL, > >>>>>>> - 0, NULL); > >>>>>>> + struct pardev_cb pdev_cb = { > >>>>>>> + .preempt = NULL, > >>>>>>> + .wakeup = NULL, > >>>>>>> + .private = NULL, > >>>>>>> + .irq_func = NULL, > >>>>>>> + .flags = 0, > >>>>>>> + }; > >>>>>>> + > >>>>>>> + /* > >>>>>>> + * Specify the device number as SNDRV_CARDS + 1 so that the > >>>>>>> + * device id alloted to this temporary device will never clash > >>>>>>> + * with an actual device already registered. > >>>>>>> + */ > >>>>>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > >>>>>>> + SNDRV_CARDS + 1); > >>>>>> > >>>>>> Hmm, doesn't this result in a device name like "xxx.33" ? > >>>>> > >>>>> yes, it will. But this is a temoporary device just to check if the > >>>>> sound card is connected to that particular parallel port or not. After > >>>>> checking this device is immediately unregistered. My idea here was to > >>>>> have a device number which will never clash with another device number. > >>>>> And we can never have a device like "xxx.33", so no conflict. :) > >>>> > >>>> Ah, this is the temporary one. If so, does it make sense to convert > >>>> this to dev_model one? This means that the device will be notified to > >>>> udev even though this is a temporary one to be removed immediately. > >>> > >>> But since we are registering a device it should ideally follow the > >>> dev_model. > >> > >> We shouldn't advertise the device that shouldn't be handled by the > >> user-space. The device you're trying to register there is the one > >> that lives only shortly just for probing the address. > >> > >> > >>>> It's what we'd want to avoid. The function serves just as probing the > >>>> availability of the given port, not really registering anything > >>>> there. > >>> > >>> To my understanding, it is probing for the availability of the port and > >>> it is also calling portman_probe() which is initializing hardware > >>> handshake lines to midi box and checking if the portman card is > >>> connected to that parallel port or not. > >>> > >>>> > >>>> That is, we need to change the registration flow itself if we really > >>>> want to move dev_model for the whole. > >>> > >>> Any hint, how to register then? > >>> Without probing (reading and writing to that port) I can not know if > >>> that port is having the card and to use the port I need to register a > >>> device with that port. > >> > >> Just returning the error at probe of the parport device itself instead > >> of doing the probe twice? The current way is racy in anyway. > > > > ... and the problem with that is, there is no way to check whether > > your upcoming change works correctly without the hardware. It would > > be no longer a "cleanup", and it's risky to do that blindly. > > Yes. That is why I try to change the driver with the minimum possible > change. But it's no 100% compatible transition. That's the first problem. > > I appreciate your work, but it doesn't look worthy enough. If we're > > trying to eliminate the all old-style parport code from the kernel > > code, OK, it's an ambitious project and we may consider taking a risk > > of breakage. Is that the case? > > Yes, the old api is supposed to be removed and we should only have the > device model api. I was expecting to remove the old API by 4.7. > Is there any way to get the hardware? No, unfortunately. It's an old hardware, after all. It's difficult to find even a decent machine with a parallel port... Takashi
On Saturday 06 February 2016 12:41 AM, Takashi Iwai wrote: > On Fri, 05 Feb 2016 18:21:46 +0100, > Sudip Mukherjee wrote: >> >> On Friday 05 February 2016 10:36 PM, Takashi Iwai wrote: >>> On Fri, 05 Feb 2016 18:01:16 +0100, >>> Takashi Iwai wrote: >>>> >>>> On Fri, 05 Feb 2016 17:50:51 +0100, >>>> Sudip Mukherjee wrote: >>>>> >>>>> On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: >>>>>> On Fri, 05 Feb 2016 07:17:06 +0100, >>>>>> Sudip Mukherjee wrote: >>>>>>> >>>>>>> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: >>>>>>>> On Thu, 04 Feb 2016 17:38:23 +0100, >>>>>>>> Sudip Mukherjee wrote: >>>>>>>>> >>>>>>>>> Modify portman driver to use the new parallel port device model. >>>>>>>>> The advantage of using the device model is that the device gets binded >>>>>>>>> to the hardware, we get the feature of hotplug, we can bind/unbind >>>>>>>>> the driver at runtime. >>>>>>>>> The only change is in the way the driver gets registered with the >>>>>>>>> parallel port subsystem and so as a result there is no user visible >>>>>>>>> change or any chance of regression. >>>>>>>>> >>>>>>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> >>>>>>>>> --- >>>>>>>>> >>>>>>>>> v3: changed commit message >>>>>>>>> v2: >>>>>>>>> 1. pardev_cb is initialized while declaring, thus removing the use of >>>>>>>>> memset. >>>>>>>>> 2. used pdev->id. >>>>>>>>> 3. v1 did not have the parport probe callback, but >>>>>>>>> we will need the probe callback for binding as the name of the driver >>>>>>>>> and the name of the device is different. >>>>>>>>> 4. in v1 I missed modifying snd_portman_probe_port(). >>>>>>>>> >>>>>>>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ >>>>>>>>> 1 file changed, 39 insertions(+), 14 deletions(-) >>>>>>>>> >>>>>>>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c >>>>>>>>> index 172685d..a22f56c 100644 >>>>>>>>> --- a/sound/drivers/portman2x4.c >>>>>>>>> +++ b/sound/drivers/portman2x4.c >>>>>>>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) >>>>>>>>> { >>>>>>>>> struct pardevice *pardev; >>>>>>>>> int res; >>>>>>>>> - >>>>>>>>> - pardev = parport_register_device(p, DRIVER_NAME, >>>>>>>>> - NULL, NULL, NULL, >>>>>>>>> - 0, NULL); >>>>>>>>> + struct pardev_cb pdev_cb = { >>>>>>>>> + .preempt = NULL, >>>>>>>>> + .wakeup = NULL, >>>>>>>>> + .private = NULL, >>>>>>>>> + .irq_func = NULL, >>>>>>>>> + .flags = 0, >>>>>>>>> + }; >>>>>>>>> + >>>>>>>>> + /* >>>>>>>>> + * Specify the device number as SNDRV_CARDS + 1 so that the >>>>>>>>> + * device id alloted to this temporary device will never clash >>>>>>>>> + * with an actual device already registered. >>>>>>>>> + */ >>>>>>>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, >>>>>>>>> + SNDRV_CARDS + 1); >>>>>>>> >>>>>>>> Hmm, doesn't this result in a device name like "xxx.33" ? >>>>>>> >>>>>>> yes, it will. But this is a temoporary device just to check if the >>>>>>> sound card is connected to that particular parallel port or not. After >>>>>>> checking this device is immediately unregistered. My idea here was to >>>>>>> have a device number which will never clash with another device number. >>>>>>> And we can never have a device like "xxx.33", so no conflict. :) >>>>>> >>>>>> Ah, this is the temporary one. If so, does it make sense to convert >>>>>> this to dev_model one? This means that the device will be notified to >>>>>> udev even though this is a temporary one to be removed immediately. >>>>> >>>>> But since we are registering a device it should ideally follow the >>>>> dev_model. >>>> >>>> We shouldn't advertise the device that shouldn't be handled by the >>>> user-space. The device you're trying to register there is the one >>>> that lives only shortly just for probing the address. >>>> >>>> >>>>>> It's what we'd want to avoid. The function serves just as probing the >>>>>> availability of the given port, not really registering anything >>>>>> there. >>>>> >>>>> To my understanding, it is probing for the availability of the port and >>>>> it is also calling portman_probe() which is initializing hardware >>>>> handshake lines to midi box and checking if the portman card is >>>>> connected to that parallel port or not. >>>>> >>>>>> >>>>>> That is, we need to change the registration flow itself if we really >>>>>> want to move dev_model for the whole. >>>>> >>>>> Any hint, how to register then? >>>>> Without probing (reading and writing to that port) I can not know if >>>>> that port is having the card and to use the port I need to register a >>>>> device with that port. >>>> >>>> Just returning the error at probe of the parport device itself instead >>>> of doing the probe twice? The current way is racy in anyway. >>> >>> ... and the problem with that is, there is no way to check whether >>> your upcoming change works correctly without the hardware. It would >>> be no longer a "cleanup", and it's risky to do that blindly. >> >> Yes. That is why I try to change the driver with the minimum possible >> change. > > But it's no 100% compatible transition. That's the first problem. Well, the first problem that i can see is using the same fixed number as the temporary device, so we can have a race there. Another problem might be that the same device number can be tried for platform device. BTW, why do we need the platform device here? we can directly probe for the device and register the sound card if the device is available from the attach function (now match_port). And the device number can be automatically generated. I think that will solve many of the problems. But the changes without checking on hardware will be risky again. > >>> I appreciate your work, but it doesn't look worthy enough. If we're >>> trying to eliminate the all old-style parport code from the kernel >>> code, OK, it's an ambitious project and we may consider taking a risk >>> of breakage. Is that the case? >> >> Yes, the old api is supposed to be removed and we should only have the >> device model api. I was expecting to remove the old API by 4.7. >> Is there any way to get the hardware? > > No, unfortunately. It's an old hardware, after all. It's difficult > to find even a decent machine with a parallel port... I have an i5 with an onboard parallel port, additionally one more pci card parallel port. So what do you suggest? how should we approach? regards sudip
On Sun, 07 Feb 2016 15:49:34 +0100, Sudip Mukherjee wrote: > > On Saturday 06 February 2016 12:41 AM, Takashi Iwai wrote: > > On Fri, 05 Feb 2016 18:21:46 +0100, > > Sudip Mukherjee wrote: > >> > >> On Friday 05 February 2016 10:36 PM, Takashi Iwai wrote: > >>> On Fri, 05 Feb 2016 18:01:16 +0100, > >>> Takashi Iwai wrote: > >>>> > >>>> On Fri, 05 Feb 2016 17:50:51 +0100, > >>>> Sudip Mukherjee wrote: > >>>>> > >>>>> On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: > >>>>>> On Fri, 05 Feb 2016 07:17:06 +0100, > >>>>>> Sudip Mukherjee wrote: > >>>>>>> > >>>>>>> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > >>>>>>>> On Thu, 04 Feb 2016 17:38:23 +0100, > >>>>>>>> Sudip Mukherjee wrote: > >>>>>>>>> > >>>>>>>>> Modify portman driver to use the new parallel port device model. > >>>>>>>>> The advantage of using the device model is that the device gets binded > >>>>>>>>> to the hardware, we get the feature of hotplug, we can bind/unbind > >>>>>>>>> the driver at runtime. > >>>>>>>>> The only change is in the way the driver gets registered with the > >>>>>>>>> parallel port subsystem and so as a result there is no user visible > >>>>>>>>> change or any chance of regression. > >>>>>>>>> > >>>>>>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > >>>>>>>>> --- > >>>>>>>>> > >>>>>>>>> v3: changed commit message > >>>>>>>>> v2: > >>>>>>>>> 1. pardev_cb is initialized while declaring, thus removing the use of > >>>>>>>>> memset. > >>>>>>>>> 2. used pdev->id. > >>>>>>>>> 3. v1 did not have the parport probe callback, but > >>>>>>>>> we will need the probe callback for binding as the name of the driver > >>>>>>>>> and the name of the device is different. > >>>>>>>>> 4. in v1 I missed modifying snd_portman_probe_port(). > >>>>>>>>> > >>>>>>>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > >>>>>>>>> 1 file changed, 39 insertions(+), 14 deletions(-) > >>>>>>>>> > >>>>>>>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > >>>>>>>>> index 172685d..a22f56c 100644 > >>>>>>>>> --- a/sound/drivers/portman2x4.c > >>>>>>>>> +++ b/sound/drivers/portman2x4.c > >>>>>>>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > >>>>>>>>> { > >>>>>>>>> struct pardevice *pardev; > >>>>>>>>> int res; > >>>>>>>>> - > >>>>>>>>> - pardev = parport_register_device(p, DRIVER_NAME, > >>>>>>>>> - NULL, NULL, NULL, > >>>>>>>>> - 0, NULL); > >>>>>>>>> + struct pardev_cb pdev_cb = { > >>>>>>>>> + .preempt = NULL, > >>>>>>>>> + .wakeup = NULL, > >>>>>>>>> + .private = NULL, > >>>>>>>>> + .irq_func = NULL, > >>>>>>>>> + .flags = 0, > >>>>>>>>> + }; > >>>>>>>>> + > >>>>>>>>> + /* > >>>>>>>>> + * Specify the device number as SNDRV_CARDS + 1 so that the > >>>>>>>>> + * device id alloted to this temporary device will never clash > >>>>>>>>> + * with an actual device already registered. > >>>>>>>>> + */ > >>>>>>>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > >>>>>>>>> + SNDRV_CARDS + 1); > >>>>>>>> > >>>>>>>> Hmm, doesn't this result in a device name like "xxx.33" ? > >>>>>>> > >>>>>>> yes, it will. But this is a temoporary device just to check if the > >>>>>>> sound card is connected to that particular parallel port or not. After > >>>>>>> checking this device is immediately unregistered. My idea here was to > >>>>>>> have a device number which will never clash with another device number. > >>>>>>> And we can never have a device like "xxx.33", so no conflict. :) > >>>>>> > >>>>>> Ah, this is the temporary one. If so, does it make sense to convert > >>>>>> this to dev_model one? This means that the device will be notified to > >>>>>> udev even though this is a temporary one to be removed immediately. > >>>>> > >>>>> But since we are registering a device it should ideally follow the > >>>>> dev_model. > >>>> > >>>> We shouldn't advertise the device that shouldn't be handled by the > >>>> user-space. The device you're trying to register there is the one > >>>> that lives only shortly just for probing the address. > >>>> > >>>> > >>>>>> It's what we'd want to avoid. The function serves just as probing the > >>>>>> availability of the given port, not really registering anything > >>>>>> there. > >>>>> > >>>>> To my understanding, it is probing for the availability of the port and > >>>>> it is also calling portman_probe() which is initializing hardware > >>>>> handshake lines to midi box and checking if the portman card is > >>>>> connected to that parallel port or not. > >>>>> > >>>>>> > >>>>>> That is, we need to change the registration flow itself if we really > >>>>>> want to move dev_model for the whole. > >>>>> > >>>>> Any hint, how to register then? > >>>>> Without probing (reading and writing to that port) I can not know if > >>>>> that port is having the card and to use the port I need to register a > >>>>> device with that port. > >>>> > >>>> Just returning the error at probe of the parport device itself instead > >>>> of doing the probe twice? The current way is racy in anyway. > >>> > >>> ... and the problem with that is, there is no way to check whether > >>> your upcoming change works correctly without the hardware. It would > >>> be no longer a "cleanup", and it's risky to do that blindly. > >> > >> Yes. That is why I try to change the driver with the minimum possible > >> change. > > > > But it's no 100% compatible transition. That's the first problem. > > Well, the first problem that i can see is using the same fixed number as > the temporary device, so we can have a race there. The original code uses parport_register_port() and this assigns a new temporary number by itself. Well, the issue is cosmetic, but... > Another problem might > be that the same device number can be tried for platform device. > > BTW, why do we need the platform device here? we can directly probe for > the device and register the sound card if the device is available from > the attach function (now match_port). And the device number can be > automatically generated. I think that will solve many of the problems. > But the changes without checking on hardware will be risky again. ... that's the only and biggest problem. The whole rewrite needs the check with the actual hardware, ideally. > >>> I appreciate your work, but it doesn't look worthy enough. If we're > >>> trying to eliminate the all old-style parport code from the kernel > >>> code, OK, it's an ambitious project and we may consider taking a risk > >>> of breakage. Is that the case? > >> > >> Yes, the old api is supposed to be removed and we should only have the > >> device model api. I was expecting to remove the old API by 4.7. > >> Is there any way to get the hardware? > > > > No, unfortunately. It's an old hardware, after all. It's difficult > > to find even a decent machine with a parallel port... > > I have an i5 with an onboard parallel port, additionally one more pci > card parallel port. > So what do you suggest? how should we approach? This really depends on the demand. As already mentioned, if your change is about getting rid of the whole legacy parport_register_port() and its old API, it'd be worth to take a risk. But then you should really concentrate only on that. Just convert it without playing too much with white space changes, etc, and make it in a series of the whole patchset (or at least show a "big picture"). thanks, Takashi
On Tue, Feb 09, 2016 at 12:32:55PM +0100, Takashi Iwai wrote: > On Sun, 07 Feb 2016 15:49:34 +0100, > Sudip Mukherjee wrote: > > > > On Saturday 06 February 2016 12:41 AM, Takashi Iwai wrote: > > > On Fri, 05 Feb 2016 18:21:46 +0100, > > > Sudip Mukherjee wrote: > > >> > > >> On Friday 05 February 2016 10:36 PM, Takashi Iwai wrote: > > >>> On Fri, 05 Feb 2016 18:01:16 +0100, > > >>> Takashi Iwai wrote: > > >>>> > > >>>> On Fri, 05 Feb 2016 17:50:51 +0100, > > >>>> Sudip Mukherjee wrote: > > >>>>> > > >>>>> On Friday 05 February 2016 05:25 PM, Takashi Iwai wrote: > > >>>>>> On Fri, 05 Feb 2016 07:17:06 +0100, > > >>>>>> Sudip Mukherjee wrote: > > >>>>>>> > > >>>>>>> On Thu, Feb 04, 2016 at 05:51:07PM +0100, Takashi Iwai wrote: > > >>>>>>>> On Thu, 04 Feb 2016 17:38:23 +0100, > > >>>>>>>> Sudip Mukherjee wrote: > > >>>>>>>>> > > >>>>>>>>> Modify portman driver to use the new parallel port device model. > > >>>>>>>>> The advantage of using the device model is that the device gets binded > > >>>>>>>>> to the hardware, we get the feature of hotplug, we can bind/unbind > > >>>>>>>>> the driver at runtime. > > >>>>>>>>> The only change is in the way the driver gets registered with the > > >>>>>>>>> parallel port subsystem and so as a result there is no user visible > > >>>>>>>>> change or any chance of regression. > > >>>>>>>>> > > >>>>>>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> > > >>>>>>>>> --- > > >>>>>>>>> > > >>>>>>>>> v3: changed commit message > > >>>>>>>>> v2: > > >>>>>>>>> 1. pardev_cb is initialized while declaring, thus removing the use of > > >>>>>>>>> memset. > > >>>>>>>>> 2. used pdev->id. > > >>>>>>>>> 3. v1 did not have the parport probe callback, but > > >>>>>>>>> we will need the probe callback for binding as the name of the driver > > >>>>>>>>> and the name of the device is different. > > >>>>>>>>> 4. in v1 I missed modifying snd_portman_probe_port(). > > >>>>>>>>> > > >>>>>>>>> sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ > > >>>>>>>>> 1 file changed, 39 insertions(+), 14 deletions(-) > > >>>>>>>>> > > >>>>>>>>> diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c > > >>>>>>>>> index 172685d..a22f56c 100644 > > >>>>>>>>> --- a/sound/drivers/portman2x4.c > > >>>>>>>>> +++ b/sound/drivers/portman2x4.c > > >>>>>>>>> @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) > > >>>>>>>>> { > > >>>>>>>>> struct pardevice *pardev; > > >>>>>>>>> int res; > > >>>>>>>>> - > > >>>>>>>>> - pardev = parport_register_device(p, DRIVER_NAME, > > >>>>>>>>> - NULL, NULL, NULL, > > >>>>>>>>> - 0, NULL); > > >>>>>>>>> + struct pardev_cb pdev_cb = { > > >>>>>>>>> + .preempt = NULL, > > >>>>>>>>> + .wakeup = NULL, > > >>>>>>>>> + .private = NULL, > > >>>>>>>>> + .irq_func = NULL, > > >>>>>>>>> + .flags = 0, > > >>>>>>>>> + }; > > >>>>>>>>> + > > >>>>>>>>> + /* > > >>>>>>>>> + * Specify the device number as SNDRV_CARDS + 1 so that the > > >>>>>>>>> + * device id alloted to this temporary device will never clash > > >>>>>>>>> + * with an actual device already registered. > > >>>>>>>>> + */ > > >>>>>>>>> + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, > > >>>>>>>>> + SNDRV_CARDS + 1); > > >>>>>>>> > > >>>>>>>> Hmm, doesn't this result in a device name like "xxx.33" ? > > >>>>>>> > > >>>>>>> yes, it will. But this is a temoporary device just to check if the > > >>>>>>> sound card is connected to that particular parallel port or not. After > > >>>>>>> checking this device is immediately unregistered. My idea here was to > > >>>>>>> have a device number which will never clash with another device number. > > >>>>>>> And we can never have a device like "xxx.33", so no conflict. :) > > >>>>>> > > >>>>>> Ah, this is the temporary one. If so, does it make sense to convert > > >>>>>> this to dev_model one? This means that the device will be notified to > > >>>>>> udev even though this is a temporary one to be removed immediately. > > >>>>> > > >>>>> But since we are registering a device it should ideally follow the > > >>>>> dev_model. > > >>>> > > >>>> We shouldn't advertise the device that shouldn't be handled by the > > >>>> user-space. The device you're trying to register there is the one > > >>>> that lives only shortly just for probing the address. > > >>>> > > >>>> > > >>>>>> It's what we'd want to avoid. The function serves just as probing the > > >>>>>> availability of the given port, not really registering anything > > >>>>>> there. > > >>>>> > > >>>>> To my understanding, it is probing for the availability of the port and > > >>>>> it is also calling portman_probe() which is initializing hardware > > >>>>> handshake lines to midi box and checking if the portman card is > > >>>>> connected to that parallel port or not. > > >>>>> > > >>>>>> > > >>>>>> That is, we need to change the registration flow itself if we really > > >>>>>> want to move dev_model for the whole. > > >>>>> > > >>>>> Any hint, how to register then? > > >>>>> Without probing (reading and writing to that port) I can not know if > > >>>>> that port is having the card and to use the port I need to register a > > >>>>> device with that port. > > >>>> > > >>>> Just returning the error at probe of the parport device itself instead > > >>>> of doing the probe twice? The current way is racy in anyway. > > >>> > > >>> ... and the problem with that is, there is no way to check whether > > >>> your upcoming change works correctly without the hardware. It would > > >>> be no longer a "cleanup", and it's risky to do that blindly. > > >> > > >> Yes. That is why I try to change the driver with the minimum possible > > >> change. > > > > > > But it's no 100% compatible transition. That's the first problem. > > > > Well, the first problem that i can see is using the same fixed number as > > the temporary device, so we can have a race there. > > The original code uses parport_register_port() and this assigns a new > temporary number by itself. Well, the issue is cosmetic, but... I think you mean parport_register_device()... > > > Another problem might > > be that the same device number can be tried for platform device. > > > > BTW, why do we need the platform device here? we can directly probe for > > the device and register the sound card if the device is available from > > the attach function (now match_port). And the device number can be > > automatically generated. I think that will solve many of the problems. > > But the changes without checking on hardware will be risky again. > > ... that's the only and biggest problem. The whole rewrite needs the > check with the actual hardware, ideally. :( If I get the chance to rewrite I will remove the platform device. > > > > >>> I appreciate your work, but it doesn't look worthy enough. If we're > > >>> trying to eliminate the all old-style parport code from the kernel > > >>> code, OK, it's an ambitious project and we may consider taking a risk > > >>> of breakage. Is that the case? > > >> > > >> Yes, the old api is supposed to be removed and we should only have the > > >> device model api. I was expecting to remove the old API by 4.7. > > >> Is there any way to get the hardware? > > > > > > No, unfortunately. It's an old hardware, after all. It's difficult > > > to find even a decent machine with a parallel port... > > > > I have an i5 with an onboard parallel port, additionally one more pci > > card parallel port. > > So what do you suggest? how should we approach? > > This really depends on the demand. As already mentioned, if your > change is about getting rid of the whole legacy > parport_register_port() and its old API, it'd be worth to take a > risk. But then you should really concentrate only on that. Just > convert it without playing too much with white space changes, etc, and > make it in a series of the whole patchset (or at least show a "big > picture"). But since all of it depends on old hardware so I am approaching very slowly. Only 2 - 3 drivers converterd in one release and I wait for any news about some regression. Fortunately till now no regression, and some of the other drivers (panel, joystick, paride, i2c-parport etc.) were also tested after the change. The plan is to convert all drivers using parport_register_device() to parport_register_dev_model() first. Infact i have systems with parallel port but no hardware to check the daisy chain so I can not touch the old API related to that. I will send you the modified patch after removing that temp device. regards sudip
diff --git a/sound/drivers/portman2x4.c b/sound/drivers/portman2x4.c index 172685d..a22f56c 100644 --- a/sound/drivers/portman2x4.c +++ b/sound/drivers/portman2x4.c @@ -650,10 +650,21 @@ static int snd_portman_probe_port(struct parport *p) { struct pardevice *pardev; int res; - - pardev = parport_register_device(p, DRIVER_NAME, - NULL, NULL, NULL, - 0, NULL); + struct pardev_cb pdev_cb = { + .preempt = NULL, + .wakeup = NULL, + .private = NULL, + .irq_func = NULL, + .flags = 0, + }; + + /* + * Specify the device number as SNDRV_CARDS + 1 so that the + * device id alloted to this temporary device will never clash + * with an actual device already registered. + */ + pardev = parport_register_dev_model(p, DRIVER_NAME, &pdev_cb, + SNDRV_CARDS + 1); if (!pardev) return -EIO; @@ -703,10 +714,20 @@ static void snd_portman_detach(struct parport *p) /* nothing to do here */ } +static int snd_portman_dev_probe(struct pardevice *pardev) +{ + if (strcmp(pardev->name, DRIVER_NAME)) + return -ENODEV; + + return 0; +} + static struct parport_driver portman_parport_driver = { - .name = "portman2x4", - .attach = snd_portman_attach, - .detach = snd_portman_detach + .name = "portman2x4", + .probe = snd_portman_dev_probe, + .match_port = snd_portman_attach, + .detach = snd_portman_detach, + .devmodel = true, }; /********************************************************************* @@ -734,6 +755,12 @@ static int snd_portman_probe(struct platform_device *pdev) struct snd_card *card = NULL; struct portman *pm = NULL; int err; + struct pardev_cb portman_cb = { + .preempt = NULL, + .wakeup = NULL, + .irq_func = snd_portman_interrupt, /* ISR */ + .flags = PARPORT_DEV_EXCL, /* flags */ + }; p = platform_get_drvdata(pdev); platform_set_drvdata(pdev, NULL); @@ -758,13 +785,11 @@ static int snd_portman_probe(struct platform_device *pdev) sprintf(card->longname, "%s at 0x%lx, irq %i", card->shortname, p->base, p->irq); - pardev = parport_register_device(p, /* port */ - DRIVER_NAME, /* name */ - NULL, /* preempt */ - NULL, /* wakeup */ - snd_portman_interrupt, /* ISR */ - PARPORT_DEV_EXCL, /* flags */ - (void *)card); /* private */ + portman_cb.private = card; /* private */ + pardev = parport_register_dev_model(p, /* port */ + DRIVER_NAME, /* name */ + &portman_cb, /* callbacks */ + pdev->id); /* device number */ if (pardev == NULL) { snd_printd("Cannot register pardevice\n"); err = -EIO;
Modify portman driver to use the new parallel port device model. The advantage of using the device model is that the device gets binded to the hardware, we get the feature of hotplug, we can bind/unbind the driver at runtime. The only change is in the way the driver gets registered with the parallel port subsystem and so as a result there is no user visible change or any chance of regression. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> --- v3: changed commit message v2: 1. pardev_cb is initialized while declaring, thus removing the use of memset. 2. used pdev->id. 3. v1 did not have the parport probe callback, but we will need the probe callback for binding as the name of the driver and the name of the device is different. 4. in v1 I missed modifying snd_portman_probe_port(). sound/drivers/portman2x4.c | 53 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 39 insertions(+), 14 deletions(-)