| Message ID | 1591b6cf2025fa95a13e3b7dde52aa0e0bde0bb4.1452105878.git.shuahkh@osg.samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Em Wed, 6 Jan 2016 13:27:04 -0700 Shuah Khan <shuahkh@osg.samsung.com> escreveu: > Checking for tuner availability from frontend thread start > disrupts video stream. Change to check for tuner and start > pipeline from frontend open instead and stop pipeline from > frontend release. That's wrong, as DVB can be opened on read-only mode, where it won't be changing anything. Also, I don't think POSIX allows to return an error like EBUSY on open: http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html > In addition, make a change to invoke > enable_source and disable_source handlers to check for > tuner availability. The enable_source handler finds tuner > entity connected to the decoder and check is it is available > or busy. If tuner is available, link is activated and pipeline > is started. The disable_source handler to deactivate and stop > the pipeline. dvb_enable_media_tuner() is removed as it is no > longer necessary with dvb invoking enable_source and > disable_source handlers. pipe_start_entity field is removed > and pipe field is moved to dvb_frontend from dvb_frontend_private. > > Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> > --- > drivers/media/dvb-core/dvb_frontend.c | 139 +++++----------------------------- > drivers/media/dvb-core/dvb_frontend.h | 3 + > 2 files changed, 24 insertions(+), 118 deletions(-) > > diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c > index 4008064..c15f3d8 100644 > --- a/drivers/media/dvb-core/dvb_frontend.c > +++ b/drivers/media/dvb-core/dvb_frontend.c > @@ -131,11 +131,6 @@ struct dvb_frontend_private { > int quality; > unsigned int check_wrapped; > enum dvbfe_search algo_status; > - > -#if defined(CONFIG_MEDIA_CONTROLLER_DVB) > - struct media_pipeline pipe; > - struct media_entity *pipe_start_entity; > -#endif > }; > > static void dvb_frontend_wakeup(struct dvb_frontend *fe); > @@ -596,104 +591,12 @@ static void dvb_frontend_wakeup(struct dvb_frontend *fe) > wake_up_interruptible(&fepriv->wait_queue); > } > > -/** > - * dvb_enable_media_tuner() - tries to enable the DVB tuner > - * > - * @fe: struct dvb_frontend pointer > - * > - * This function ensures that just one media tuner is enabled for a given > - * frontend. It has two different behaviors: > - * - For trivial devices with just one tuner: > - * it just enables the existing tuner->fe link > - * - For devices with more than one tuner: > - * It is up to the driver to implement the logic that will enable one tuner > - * and disable the other ones. However, if more than one tuner is enabled for > - * the same frontend, it will print an error message and return -EINVAL. > - * > - * At return, it will return the error code returned by media_entity_setup_link, > - * or 0 if everything is OK, if no tuner is linked to the frontend or if the > - * mdev is NULL. > - */ > -#ifdef CONFIG_MEDIA_CONTROLLER_DVB > -static int dvb_enable_media_tuner(struct dvb_frontend *fe) > -{ > - struct dvb_frontend_private *fepriv = fe->frontend_priv; > - struct dvb_adapter *adapter = fe->dvb; > - struct media_device *mdev = adapter->mdev; > - struct media_entity *entity, *source; > - struct media_link *link, *found_link = NULL; > - int ret, n_links = 0, active_links = 0; > - > - fepriv->pipe_start_entity = NULL; > - > - if (!mdev) > - return 0; > - > - entity = fepriv->dvbdev->entity; > - fepriv->pipe_start_entity = entity; > - > - list_for_each_entry(link, &entity->links, list) { > - if (link->sink->entity == entity) { > - found_link = link; > - n_links++; > - if (link->flags & MEDIA_LNK_FL_ENABLED) > - active_links++; > - } > - } > - > - if (!n_links || active_links == 1 || !found_link) > - return 0; > - > - /* > - * If a frontend has more than one tuner linked, it is up to the driver > - * to select with one will be the active one, as the frontend core can't > - * guess. If the driver doesn't do that, it is a bug. > - */ > - if (n_links > 1 && active_links != 1) { > - dev_err(fe->dvb->device, > - "WARNING: there are %d active links among %d tuners. This is a driver's bug!\n", > - active_links, n_links); > - return -EINVAL; > - } > - > - source = found_link->source->entity; > - fepriv->pipe_start_entity = source; > - list_for_each_entry(link, &source->links, list) { > - struct media_entity *sink; > - int flags = 0; > - > - sink = link->sink->entity; > - if (sink == entity) > - flags = MEDIA_LNK_FL_ENABLED; > - > - ret = media_entity_setup_link(link, flags); > - if (ret) { > - dev_err(fe->dvb->device, > - "Couldn't change link %s->%s to %s. Error %d\n", > - source->name, sink->name, > - flags ? "enabled" : "disabled", > - ret); > - return ret; > - } else > - dev_dbg(fe->dvb->device, > - "link %s->%s was %s\n", > - source->name, sink->name, > - flags ? "ENABLED" : "disabled"); > - } > - return 0; > -} > -#endif > - > static int dvb_frontend_thread(void *data) > { > struct dvb_frontend *fe = data; > struct dvb_frontend_private *fepriv = fe->frontend_priv; > enum fe_status s; > enum dvbfe_algo algo; > -#ifdef CONFIG_MEDIA_CONTROLLER_DVB > - int ret; > -#endif > - > bool re_tune = false; > bool semheld = false; > > @@ -706,20 +609,6 @@ static int dvb_frontend_thread(void *data) > fepriv->wakeup = 0; > fepriv->reinitialise = 0; > > -#ifdef CONFIG_MEDIA_CONTROLLER_DVB > - ret = dvb_enable_media_tuner(fe); > - if (ret) { > - /* FIXME: return an error if it fails */ > - dev_info(fe->dvb->device, > - "proceeding with FE task\n"); > - } else if (fepriv->pipe_start_entity) { > - ret = media_entity_pipeline_start(fepriv->pipe_start_entity, > - &fepriv->pipe); > - if (ret) > - return ret; > - } > -#endif > - > dvb_frontend_init(fe); > > set_freezable(); > @@ -829,12 +718,6 @@ restart: > } > } > > -#ifdef CONFIG_MEDIA_CONTROLLER_DVB > - if (fepriv->pipe_start_entity) > - media_entity_pipeline_stop(fepriv->pipe_start_entity); > - fepriv->pipe_start_entity = NULL; > -#endif > - > if (dvb_powerdown_on_sleep) { > if (fe->ops.set_voltage) > fe->ops.set_voltage(fe, SEC_VOLTAGE_OFF); > @@ -2612,9 +2495,20 @@ static int dvb_frontend_open(struct inode *inode, struct file *file) > fepriv->tone = -1; > fepriv->voltage = -1; > > +#ifdef CONFIG_MEDIA_CONTROLLER_DVB > + if (fe->dvb->mdev && fe->dvb->mdev->enable_source) { > + ret = fe->dvb->mdev->enable_source(dvbdev->entity, > + &fe->pipe); > + if (ret) { > + dev_err(fe->dvb->device, > + "Tuner is busy. Error %d\n", ret); > + goto err2; > + } > + } > +#endif > ret = dvb_frontend_start (fe); > if (ret) > - goto err2; > + goto err3; > > /* empty event queue */ > fepriv->events.eventr = fepriv->events.eventw = 0; > @@ -2624,7 +2518,12 @@ static int dvb_frontend_open(struct inode *inode, struct file *file) > mutex_unlock (&adapter->mfe_lock); > return ret; > > +err3: > +#ifdef CONFIG_MEDIA_CONTROLLER_DVB > + if (fe->dvb->mdev && fe->dvb->mdev->disable_source) > + fe->dvb->mdev->disable_source(dvbdev->entity); > err2: > +#endif > dvb_generic_release(inode, file); > err1: > if (dvbdev->users == -1 && fe->ops.ts_bus_ctrl) > @@ -2653,6 +2552,10 @@ static int dvb_frontend_release(struct inode *inode, struct file *file) > > if (dvbdev->users == -1) { > wake_up(&fepriv->wait_queue); > +#ifdef CONFIG_MEDIA_CONTROLLER_DVB > + if (fe->dvb->mdev && fe->dvb->mdev->disable_source) > + fe->dvb->mdev->disable_source(dvbdev->entity); > +#endif > if (fe->exit != DVB_FE_NO_EXIT) > wake_up(&dvbdev->wait_queue); > if (fe->ops.ts_bus_ctrl) > diff --git a/drivers/media/dvb-core/dvb_frontend.h b/drivers/media/dvb-core/dvb_frontend.h > index 458bcce..9466906 100644 > --- a/drivers/media/dvb-core/dvb_frontend.h > +++ b/drivers/media/dvb-core/dvb_frontend.h > @@ -686,6 +686,9 @@ struct dvb_frontend { > int (*callback)(void *adapter_priv, int component, int cmd, int arg); > int id; > unsigned int exit; > +#if defined(CONFIG_MEDIA_CONTROLLER_DVB) > + struct media_pipeline pipe; > +#endif > }; > > /** -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 28 Jan 2016 13:53:04 -0200 Mauro Carvalho Chehab <mchehab@osg.samsung.com> wrote: > Em Wed, 6 Jan 2016 13:27:04 -0700 > Shuah Khan <shuahkh@osg.samsung.com> escreveu: > > > Checking for tuner availability from frontend thread start > > disrupts video stream. Change to check for tuner and start > > pipeline from frontend open instead and stop pipeline from > > frontend release. > > That's wrong, as DVB can be opened on read-only mode, where > it won't be changing anything. > > Also, I don't think POSIX allows to return an error like EBUSY > on open: > http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html It doesn't document all the errors you may return. Quite a lot of kernel drivers return EBUSY when they are "single open" things. POSIX documents certain cases that *must* error and what the error code is. It documents certain possible failures and what their error code is. Beyond that it's up to you. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 01/28/2016 09:07 AM, One Thousand Gnomes wrote: > On Thu, 28 Jan 2016 13:53:04 -0200 > Mauro Carvalho Chehab <mchehab@osg.samsung.com> wrote: > >> Em Wed, 6 Jan 2016 13:27:04 -0700 >> Shuah Khan <shuahkh@osg.samsung.com> escreveu: >> >>> Checking for tuner availability from frontend thread start >>> disrupts video stream. Change to check for tuner and start >>> pipeline from frontend open instead and stop pipeline from >>> frontend release. >> >> That's wrong, as DVB can be opened on read-only mode, where >> it won't be changing anything. Correct. Please check the code. Tuner availability check is done when the device is opened in Write mode in the following conditional. if ((file->f_flags & O_ACCMODE) != O_RDONLY) { >> >> Also, I don't think POSIX allows to return an error like EBUSY >> on open: >> http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html > > It doesn't document all the errors you may return. Quite a lot of > kernel drivers return EBUSY when they are "single open" things. > > POSIX documents certain cases that *must* error and what the error code > is. It documents certain possible failures and what their error code is. > Beyond that it's up to you. > Returning EBUSY clearly indicates the reason why the device can't be opened in this case. thanks, -- Shuah
Em Thu, 28 Jan 2016 09:59:38 -0700 Shuah Khan <shuahkh@osg.samsung.com> escreveu: > On 01/28/2016 09:07 AM, One Thousand Gnomes wrote: > > On Thu, 28 Jan 2016 13:53:04 -0200 > > Mauro Carvalho Chehab <mchehab@osg.samsung.com> wrote: > > > >> Em Wed, 6 Jan 2016 13:27:04 -0700 > >> Shuah Khan <shuahkh@osg.samsung.com> escreveu: > >> > >>> Checking for tuner availability from frontend thread start > >>> disrupts video stream. Change to check for tuner and start > >>> pipeline from frontend open instead and stop pipeline from > >>> frontend release. > >> > >> That's wrong, as DVB can be opened on read-only mode, where > >> it won't be changing anything. > > Correct. Please check the code. Tuner availability check is > done when the device is opened in Write mode in the following > conditional. > > if ((file->f_flags & O_ACCMODE) != O_RDONLY) { OK. Thanks! Mauro , I don't think POSIX allows to return an error like EBUSY > >> on open: > >> http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html > > > > It doesn't document all the errors you may return. Quite a lot of > > kernel drivers return EBUSY when they are "single open" things. > > > > POSIX documents certain cases that *must* error and what the error code > > is. It documents certain possible failures and what their error code is. > > Beyond that it's up to you. > > > > Returning EBUSY clearly indicates the reason why the device > can't be opened in this case. > > thanks, > -- Shuah > > Thanks! Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index 4008064..c15f3d8 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -131,11 +131,6 @@ struct dvb_frontend_private { int quality; unsigned int check_wrapped; enum dvbfe_search algo_status; - -#if defined(CONFIG_MEDIA_CONTROLLER_DVB) - struct media_pipeline pipe; - struct media_entity *pipe_start_entity; -#endif }; static void dvb_frontend_wakeup(struct dvb_frontend *fe); @@ -596,104 +591,12 @@ static void dvb_frontend_wakeup(struct dvb_frontend *fe) wake_up_interruptible(&fepriv->wait_queue); } -/** - * dvb_enable_media_tuner() - tries to enable the DVB tuner - * - * @fe: struct dvb_frontend pointer - * - * This function ensures that just one media tuner is enabled for a given - * frontend. It has two different behaviors: - * - For trivial devices with just one tuner: - * it just enables the existing tuner->fe link - * - For devices with more than one tuner: - * It is up to the driver to implement the logic that will enable one tuner - * and disable the other ones. However, if more than one tuner is enabled for - * the same frontend, it will print an error message and return -EINVAL. - * - * At return, it will return the error code returned by media_entity_setup_link, - * or 0 if everything is OK, if no tuner is linked to the frontend or if the - * mdev is NULL. - */ -#ifdef CONFIG_MEDIA_CONTROLLER_DVB -static int dvb_enable_media_tuner(struct dvb_frontend *fe) -{ - struct dvb_frontend_private *fepriv = fe->frontend_priv; - struct dvb_adapter *adapter = fe->dvb; - struct media_device *mdev = adapter->mdev; - struct media_entity *entity, *source; - struct media_link *link, *found_link = NULL; - int ret, n_links = 0, active_links = 0; - - fepriv->pipe_start_entity = NULL; - - if (!mdev) - return 0; - - entity = fepriv->dvbdev->entity; - fepriv->pipe_start_entity = entity; - - list_for_each_entry(link, &entity->links, list) { - if (link->sink->entity == entity) { - found_link = link; - n_links++; - if (link->flags & MEDIA_LNK_FL_ENABLED) - active_links++; - } - } - - if (!n_links || active_links == 1 || !found_link) - return 0; - - /* - * If a frontend has more than one tuner linked, it is up to the driver - * to select with one will be the active one, as the frontend core can't - * guess. If the driver doesn't do that, it is a bug. - */ - if (n_links > 1 && active_links != 1) { - dev_err(fe->dvb->device, - "WARNING: there are %d active links among %d tuners. This is a driver's bug!\n", - active_links, n_links); - return -EINVAL; - } - - source = found_link->source->entity; - fepriv->pipe_start_entity = source; - list_for_each_entry(link, &source->links, list) { - struct media_entity *sink; - int flags = 0; - - sink = link->sink->entity; - if (sink == entity) - flags = MEDIA_LNK_FL_ENABLED; - - ret = media_entity_setup_link(link, flags); - if (ret) { - dev_err(fe->dvb->device, - "Couldn't change link %s->%s to %s. Error %d\n", - source->name, sink->name, - flags ? "enabled" : "disabled", - ret); - return ret; - } else - dev_dbg(fe->dvb->device, - "link %s->%s was %s\n", - source->name, sink->name, - flags ? "ENABLED" : "disabled"); - } - return 0; -} -#endif - static int dvb_frontend_thread(void *data) { struct dvb_frontend *fe = data; struct dvb_frontend_private *fepriv = fe->frontend_priv; enum fe_status s; enum dvbfe_algo algo; -#ifdef CONFIG_MEDIA_CONTROLLER_DVB - int ret; -#endif - bool re_tune = false; bool semheld = false; @@ -706,20 +609,6 @@ static int dvb_frontend_thread(void *data) fepriv->wakeup = 0; fepriv->reinitialise = 0; -#ifdef CONFIG_MEDIA_CONTROLLER_DVB - ret = dvb_enable_media_tuner(fe); - if (ret) { - /* FIXME: return an error if it fails */ - dev_info(fe->dvb->device, - "proceeding with FE task\n"); - } else if (fepriv->pipe_start_entity) { - ret = media_entity_pipeline_start(fepriv->pipe_start_entity, - &fepriv->pipe); - if (ret) - return ret; - } -#endif - dvb_frontend_init(fe); set_freezable(); @@ -829,12 +718,6 @@ restart: } } -#ifdef CONFIG_MEDIA_CONTROLLER_DVB - if (fepriv->pipe_start_entity) - media_entity_pipeline_stop(fepriv->pipe_start_entity); - fepriv->pipe_start_entity = NULL; -#endif - if (dvb_powerdown_on_sleep) { if (fe->ops.set_voltage) fe->ops.set_voltage(fe, SEC_VOLTAGE_OFF); @@ -2612,9 +2495,20 @@ static int dvb_frontend_open(struct inode *inode, struct file *file) fepriv->tone = -1; fepriv->voltage = -1; +#ifdef CONFIG_MEDIA_CONTROLLER_DVB + if (fe->dvb->mdev && fe->dvb->mdev->enable_source) { + ret = fe->dvb->mdev->enable_source(dvbdev->entity, + &fe->pipe); + if (ret) { + dev_err(fe->dvb->device, + "Tuner is busy. Error %d\n", ret); + goto err2; + } + } +#endif ret = dvb_frontend_start (fe); if (ret) - goto err2; + goto err3; /* empty event queue */ fepriv->events.eventr = fepriv->events.eventw = 0; @@ -2624,7 +2518,12 @@ static int dvb_frontend_open(struct inode *inode, struct file *file) mutex_unlock (&adapter->mfe_lock); return ret; +err3: +#ifdef CONFIG_MEDIA_CONTROLLER_DVB + if (fe->dvb->mdev && fe->dvb->mdev->disable_source) + fe->dvb->mdev->disable_source(dvbdev->entity); err2: +#endif dvb_generic_release(inode, file); err1: if (dvbdev->users == -1 && fe->ops.ts_bus_ctrl) @@ -2653,6 +2552,10 @@ static int dvb_frontend_release(struct inode *inode, struct file *file) if (dvbdev->users == -1) { wake_up(&fepriv->wait_queue); +#ifdef CONFIG_MEDIA_CONTROLLER_DVB + if (fe->dvb->mdev && fe->dvb->mdev->disable_source) + fe->dvb->mdev->disable_source(dvbdev->entity); +#endif if (fe->exit != DVB_FE_NO_EXIT) wake_up(&dvbdev->wait_queue); if (fe->ops.ts_bus_ctrl) diff --git a/drivers/media/dvb-core/dvb_frontend.h b/drivers/media/dvb-core/dvb_frontend.h index 458bcce..9466906 100644 --- a/drivers/media/dvb-core/dvb_frontend.h +++ b/drivers/media/dvb-core/dvb_frontend.h @@ -686,6 +686,9 @@ struct dvb_frontend { int (*callback)(void *adapter_priv, int component, int cmd, int arg); int id; unsigned int exit; +#if defined(CONFIG_MEDIA_CONTROLLER_DVB) + struct media_pipeline pipe; +#endif }; /**
Checking for tuner availability from frontend thread start disrupts video stream. Change to check for tuner and start pipeline from frontend open instead and stop pipeline from frontend release. In addition, make a change to invoke enable_source and disable_source handlers to check for tuner availability. The enable_source handler finds tuner entity connected to the decoder and check is it is available or busy. If tuner is available, link is activated and pipeline is started. The disable_source handler to deactivate and stop the pipeline. dvb_enable_media_tuner() is removed as it is no longer necessary with dvb invoking enable_source and disable_source handlers. pipe_start_entity field is removed and pipe field is moved to dvb_frontend from dvb_frontend_private. Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> --- drivers/media/dvb-core/dvb_frontend.c | 139 +++++----------------------------- drivers/media/dvb-core/dvb_frontend.h | 3 + 2 files changed, 24 insertions(+), 118 deletions(-)