diff mbox series

[v1,2/2] net: dsa: rtl8366rb: Quick fix to work with fw_devlink=on

Message ID 20210826074526.825517-3-saravanak@google.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Fix rtl8366rb issues with fw_devlink=on | expand

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Commit Message

Saravana Kannan Aug. 26, 2021, 7:45 a.m. UTC
This is just a quick fix to make this driver work with fw_devlink=on.
The proper fix might need a significant amount of rework of the driver
of the framework to use a component device model.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/net/dsa/realtek-smi-core.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Greg KH Aug. 26, 2021, 7:55 a.m. UTC | #1
On Thu, Aug 26, 2021 at 12:45:25AM -0700, Saravana Kannan wrote:
> This is just a quick fix to make this driver work with fw_devlink=on.
> The proper fix might need a significant amount of rework of the driver
> of the framework to use a component device model.
> 
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/net/dsa/realtek-smi-core.c | 7 +++++++
>  1 file changed, 7 insertions(+)

"quick" fixes are nice, but who is going to do the real work here to fix
this properly if this series is accepted?

thanks,

greg k-h
Florian Fainelli Aug. 26, 2021, 11:25 a.m. UTC | #2
On 8/26/2021 9:45 AM, Saravana Kannan wrote:
> This is just a quick fix to make this driver work with fw_devlink=on.
> The proper fix might need a significant amount of rework of the driver
> of the framework to use a component device model.
> 
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>   drivers/net/dsa/realtek-smi-core.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
> index 8e49d4f85d48..f79c174f4954 100644
> --- a/drivers/net/dsa/realtek-smi-core.c
> +++ b/drivers/net/dsa/realtek-smi-core.c
> @@ -394,6 +394,13 @@ static int realtek_smi_probe(struct platform_device *pdev)
>   	var = of_device_get_match_data(dev);
>   	np = dev->of_node;
>   
> +	/* This driver assumes the child PHYs would be probed successfully
> +	 * before this functions returns. That's not a valid assumption, but
> +	 * let fw_devlink know so that this driver continues to function with
> +	 * fw_devlink=on.
> +	 */
> +	np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;

Are we positive this is not an issue that applies generally to all DSA 
drivers?
Alvin Šipraga Aug. 26, 2021, 11:29 a.m. UTC | #3
Hi Saravana,

 From looking at the code, the Marvell DSA driver mv88e6xxx may also 
suffer from the same problem if fw_devlink=on. Maybe somebody (Andrew?) 
could test so that you know whether include a simlar patch to that 
driver in your series.

Other drivers may be effected too - as Andrew said in the other thread, 
this is not an uncommon pattern for DSA drivers.

On 8/26/21 9:45 AM, Saravana Kannan wrote:
> This is just a quick fix to make this driver work with fw_devlink=on.
> The proper fix might need a significant amount of rework of the driver
> of the framework to use a component device model.
> 
> Signed-off-by: Saravana Kannan <saravanak@google.com>

With the caveat that it's a test with my RFC rtl8365mb subdriver...

Tested-by: Alvin Šipraga <alsi@bang-olufsen.dk>

Kind regards,
Alvin

> ---
>   drivers/net/dsa/realtek-smi-core.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
> index 8e49d4f85d48..f79c174f4954 100644
> --- a/drivers/net/dsa/realtek-smi-core.c
> +++ b/drivers/net/dsa/realtek-smi-core.c
> @@ -394,6 +394,13 @@ static int realtek_smi_probe(struct platform_device *pdev)
>   	var = of_device_get_match_data(dev);
>   	np = dev->of_node;
>   
> +	/* This driver assumes the child PHYs would be probed successfully
> +	 * before this functions returns. That's not a valid assumption, but
> +	 * let fw_devlink know so that this driver continues to function with
> +	 * fw_devlink=on.
> +	 */
> +	np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;
> +
>   	smi = devm_kzalloc(dev, sizeof(*smi) + var->chip_data_sz, GFP_KERNEL);
>   	if (!smi)
>   		return -ENOMEM;
>
Saravana Kannan Aug. 26, 2021, 5:26 p.m. UTC | #4
On Thu, Aug 26, 2021 at 4:29 AM Alvin Šipraga <ALSI@bang-olufsen.dk> wrote:
>
> Hi Saravana,
>
>  From looking at the code, the Marvell DSA driver mv88e6xxx may also
> suffer from the same problem if fw_devlink=on. Maybe somebody (Andrew?)
> could test so that you know whether include a simlar patch to that
> driver in your series.
>
> Other drivers may be effected too - as Andrew said in the other thread,
> this is not an uncommon pattern for DSA drivers.
>
> On 8/26/21 9:45 AM, Saravana Kannan wrote:
> > This is just a quick fix to make this driver work with fw_devlink=on.
> > The proper fix might need a significant amount of rework of the driver
> > of the framework to use a component device model.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
>
> With the caveat that it's a test with my RFC rtl8365mb subdriver...
>
> Tested-by: Alvin Šipraga <alsi@bang-olufsen.dk>

Thanks for testing. And just to be sure we are all on the same page:
Without this patch the PHYs get handled by the Generic PHY driver.
With this patch, the PHYs are handled by their specific driver.
Correct?

-Saravana

>
> Kind regards,
> Alvin
>
> > ---
> >   drivers/net/dsa/realtek-smi-core.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
> > index 8e49d4f85d48..f79c174f4954 100644
> > --- a/drivers/net/dsa/realtek-smi-core.c
> > +++ b/drivers/net/dsa/realtek-smi-core.c
> > @@ -394,6 +394,13 @@ static int realtek_smi_probe(struct platform_device *pdev)
> >       var = of_device_get_match_data(dev);
> >       np = dev->of_node;
> >
> > +     /* This driver assumes the child PHYs would be probed successfully
> > +      * before this functions returns. That's not a valid assumption, but
> > +      * let fw_devlink know so that this driver continues to function with
> > +      * fw_devlink=on.
> > +      */
> > +     np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;
> > +
> >       smi = devm_kzalloc(dev, sizeof(*smi) + var->chip_data_sz, GFP_KERNEL);
> >       if (!smi)
> >               return -ENOMEM;
> >
Saravana Kannan Aug. 26, 2021, 5:29 p.m. UTC | #5
On Thu, Aug 26, 2021 at 4:25 AM Florian Fainelli <f.fainelli@gmail.com> wrote:
>
>
>
> On 8/26/2021 9:45 AM, Saravana Kannan wrote:
> > This is just a quick fix to make this driver work with fw_devlink=on.
> > The proper fix might need a significant amount of rework of the driver
> > of the framework to use a component device model.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > ---
> >   drivers/net/dsa/realtek-smi-core.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
> > index 8e49d4f85d48..f79c174f4954 100644
> > --- a/drivers/net/dsa/realtek-smi-core.c
> > +++ b/drivers/net/dsa/realtek-smi-core.c
> > @@ -394,6 +394,13 @@ static int realtek_smi_probe(struct platform_device *pdev)
> >       var = of_device_get_match_data(dev);
> >       np = dev->of_node;
> >
> > +     /* This driver assumes the child PHYs would be probed successfully
> > +      * before this functions returns. That's not a valid assumption, but
> > +      * let fw_devlink know so that this driver continues to function with
> > +      * fw_devlink=on.
> > +      */
> > +     np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;
>
> Are we positive this is not an issue that applies generally to all DSA
> drivers?

Possibly, but I don't know enough about that framework. Let me respond
to the email from Andrew[1] and give a summary there. We can go from
there.

[1] - https://lore.kernel.org/lkml/YSeTdb6DbHbBYabN@lunn.ch/#t
-Saravana
Alvin Šipraga Aug. 26, 2021, 6:04 p.m. UTC | #6
On 8/26/21 7:26 PM, Saravana Kannan wrote:
> On Thu, Aug 26, 2021 at 4:29 AM Alvin Šipraga <ALSI@bang-olufsen.dk> wrote:
>>
>> Hi Saravana,
>>
>>   From looking at the code, the Marvell DSA driver mv88e6xxx may also
>> suffer from the same problem if fw_devlink=on. Maybe somebody (Andrew?)
>> could test so that you know whether include a simlar patch to that
>> driver in your series.
>>
>> Other drivers may be effected too - as Andrew said in the other thread,
>> this is not an uncommon pattern for DSA drivers.
>>
>> On 8/26/21 9:45 AM, Saravana Kannan wrote:
>>> This is just a quick fix to make this driver work with fw_devlink=on.
>>> The proper fix might need a significant amount of rework of the driver
>>> of the framework to use a component device model.
>>>
>>> Signed-off-by: Saravana Kannan <saravanak@google.com>
>>
>> With the caveat that it's a test with my RFC rtl8365mb subdriver...
>>
>> Tested-by: Alvin Šipraga <alsi@bang-olufsen.dk>
> 
> Thanks for testing. And just to be sure we are all on the same page:
> Without this patch the PHYs get handled by the Generic PHY driver.
> With this patch, the PHYs are handled by their specific driver.
> Correct?

Yes, both statements are correct.

	Alvin

> 
> -Saravana
> 
>>
>> Kind regards,
>> Alvin
>>
>>> ---
>>>    drivers/net/dsa/realtek-smi-core.c | 7 +++++++
>>>    1 file changed, 7 insertions(+)
>>>
>>> diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
>>> index 8e49d4f85d48..f79c174f4954 100644
>>> --- a/drivers/net/dsa/realtek-smi-core.c
>>> +++ b/drivers/net/dsa/realtek-smi-core.c
>>> @@ -394,6 +394,13 @@ static int realtek_smi_probe(struct platform_device *pdev)
>>>        var = of_device_get_match_data(dev);
>>>        np = dev->of_node;
>>>
>>> +     /* This driver assumes the child PHYs would be probed successfully
>>> +      * before this functions returns. That's not a valid assumption, but
>>> +      * let fw_devlink know so that this driver continues to function with
>>> +      * fw_devlink=on.
>>> +      */
>>> +     np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;
>>> +
>>>        smi = devm_kzalloc(dev, sizeof(*smi) + var->chip_data_sz, GFP_KERNEL);
>>>        if (!smi)
>>>                return -ENOMEM;
>>>
diff mbox series

Patch

diff --git a/drivers/net/dsa/realtek-smi-core.c b/drivers/net/dsa/realtek-smi-core.c
index 8e49d4f85d48..f79c174f4954 100644
--- a/drivers/net/dsa/realtek-smi-core.c
+++ b/drivers/net/dsa/realtek-smi-core.c
@@ -394,6 +394,13 @@  static int realtek_smi_probe(struct platform_device *pdev)
 	var = of_device_get_match_data(dev);
 	np = dev->of_node;
 
+	/* This driver assumes the child PHYs would be probed successfully
+	 * before this functions returns. That's not a valid assumption, but
+	 * let fw_devlink know so that this driver continues to function with
+	 * fw_devlink=on.
+	 */
+	np->fwnode.flags |= FWNODE_FLAG_BROKEN_PARENT;
+
 	smi = devm_kzalloc(dev, sizeof(*smi) + var->chip_data_sz, GFP_KERNEL);
 	if (!smi)
 		return -ENOMEM;