| Message ID | 1381214401-24672-2-git-send-email-aaron.lu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tuesday, October 08, 2013 02:39:58 PM Aaron Lu wrote: > Introduce a new API for modules to query if a specific type of backlight > device has been registered. This is useful for some backlight device > provider module(e.g. ACPI video) to know if a native control > interface(e.g. the interface created by i915) is available and then do > things accordingly(e.g. avoid register its own on Win8 systems). > > Signed-off-by: Aaron Lu <aaron.lu@intel.com> > Tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com> > Tested-by: Yves-Alexis Perez <corsac@debian.org> > Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> > --- > drivers/video/backlight/backlight.c | 31 +++++++++++++++++++++++++++++++ > include/linux/backlight.h | 4 ++++ > 2 files changed, 35 insertions(+) > > diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c > index 94a403a..bf2d71d 100644 > --- a/drivers/video/backlight/backlight.c > +++ b/drivers/video/backlight/backlight.c > @@ -21,6 +21,9 @@ > #include <asm/backlight.h> > #endif > > +static struct list_head bd_list_head; > +static struct mutex bd_list_mutex; I'd prefer these two things to be called backlight_dev_list and backlight_dev_list_mutex, respectively. > + > static const char *const backlight_types[] = { > [BACKLIGHT_RAW] = "raw", > [BACKLIGHT_PLATFORM] = "platform", > @@ -349,10 +352,32 @@ struct backlight_device *backlight_device_register(const char *name, > mutex_unlock(&pmac_backlight_mutex); > #endif > > + mutex_lock(&bd_list_mutex); > + list_add(&new_bd->entry, &bd_list_head); > + mutex_unlock(&bd_list_mutex); > + > return new_bd; > } > EXPORT_SYMBOL(backlight_device_register); > > +bool backlight_device_registered(enum backlight_type type) > +{ > + bool found = false; > + struct backlight_device *bd; > + > + mutex_lock(&bd_list_mutex); > + list_for_each_entry(bd, &bd_list_head, entry) { > + if (bd->props.type == type) { > + found = true; > + break; > + } > + } Isn't it useful to be able to register more than one backlight device of the same type sometimes? > + mutex_unlock(&bd_list_mutex); > + > + return found; > +} > +EXPORT_SYMBOL(backlight_device_registered); > + > /** > * backlight_device_unregister - unregisters a backlight device object. > * @bd: the backlight device object to be unregistered and freed. > @@ -364,6 +389,10 @@ void backlight_device_unregister(struct backlight_device *bd) > if (!bd) > return; > > + mutex_lock(&bd_list_mutex); > + list_del(&bd->entry); > + mutex_unlock(&bd_list_mutex); > + > #ifdef CONFIG_PMAC_BACKLIGHT > mutex_lock(&pmac_backlight_mutex); > if (pmac_backlight == bd) > @@ -499,6 +528,8 @@ static int __init backlight_class_init(void) > > backlight_class->dev_groups = bl_device_groups; > backlight_class->pm = &backlight_class_dev_pm_ops; > + INIT_LIST_HEAD(&bd_list_head); > + mutex_init(&bd_list_mutex); > return 0; > } > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 53b7794..5f9cd96 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -100,6 +100,9 @@ struct backlight_device { > /* The framebuffer notifier block */ > struct notifier_block fb_notif; > > + /* list entry of all registered backlight devices */ > + struct list_head entry; > + > struct device dev; > }; > > @@ -123,6 +126,7 @@ extern void devm_backlight_device_unregister(struct device *dev, > struct backlight_device *bd); > extern void backlight_force_update(struct backlight_device *bd, > enum backlight_update_reason reason); > +extern bool backlight_device_registered(enum backlight_type type); > > #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) Thanks!
On 10/10/2013 08:25 AM, Rafael J. Wysocki wrote: > On Tuesday, October 08, 2013 02:39:58 PM Aaron Lu wrote: >> Introduce a new API for modules to query if a specific type of backlight >> device has been registered. This is useful for some backlight device >> provider module(e.g. ACPI video) to know if a native control >> interface(e.g. the interface created by i915) is available and then do >> things accordingly(e.g. avoid register its own on Win8 systems). >> >> Signed-off-by: Aaron Lu <aaron.lu@intel.com> >> Tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com> >> Tested-by: Yves-Alexis Perez <corsac@debian.org> >> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> >> --- >> drivers/video/backlight/backlight.c | 31 +++++++++++++++++++++++++++++++ >> include/linux/backlight.h | 4 ++++ >> 2 files changed, 35 insertions(+) >> >> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c >> index 94a403a..bf2d71d 100644 >> --- a/drivers/video/backlight/backlight.c >> +++ b/drivers/video/backlight/backlight.c >> @@ -21,6 +21,9 @@ >> #include <asm/backlight.h> >> #endif >> >> +static struct list_head bd_list_head; >> +static struct mutex bd_list_mutex; > > I'd prefer these two things to be called backlight_dev_list and > backlight_dev_list_mutex, respectively. OK. > >> + >> static const char *const backlight_types[] = { >> [BACKLIGHT_RAW] = "raw", >> [BACKLIGHT_PLATFORM] = "platform", >> @@ -349,10 +352,32 @@ struct backlight_device *backlight_device_register(const char *name, >> mutex_unlock(&pmac_backlight_mutex); >> #endif >> >> + mutex_lock(&bd_list_mutex); >> + list_add(&new_bd->entry, &bd_list_head); >> + mutex_unlock(&bd_list_mutex); >> + >> return new_bd; >> } >> EXPORT_SYMBOL(backlight_device_register); >> >> +bool backlight_device_registered(enum backlight_type type) >> +{ >> + bool found = false; >> + struct backlight_device *bd; >> + >> + mutex_lock(&bd_list_mutex); >> + list_for_each_entry(bd, &bd_list_head, entry) { >> + if (bd->props.type == type) { >> + found = true; >> + break; >> + } >> + } > > Isn't it useful to be able to register more than one backlight device of the > same type sometimes? I think so for some kind of computers. OTOH, the above function should be enough for the problem we are solving here, if someday we need to differentiate, we can enhance the code then. > >> + mutex_unlock(&bd_list_mutex); >> + >> + return found; >> +} >> +EXPORT_SYMBOL(backlight_device_registered); >> + >> /** >> * backlight_device_unregister - unregisters a backlight device object. >> * @bd: the backlight device object to be unregistered and freed. >> @@ -364,6 +389,10 @@ void backlight_device_unregister(struct backlight_device *bd) >> if (!bd) >> return; >> >> + mutex_lock(&bd_list_mutex); >> + list_del(&bd->entry); >> + mutex_unlock(&bd_list_mutex); >> + >> #ifdef CONFIG_PMAC_BACKLIGHT >> mutex_lock(&pmac_backlight_mutex); >> if (pmac_backlight == bd) >> @@ -499,6 +528,8 @@ static int __init backlight_class_init(void) >> >> backlight_class->dev_groups = bl_device_groups; >> backlight_class->pm = &backlight_class_dev_pm_ops; >> + INIT_LIST_HEAD(&bd_list_head); >> + mutex_init(&bd_list_mutex); >> return 0; >> } >> >> diff --git a/include/linux/backlight.h b/include/linux/backlight.h >> index 53b7794..5f9cd96 100644 >> --- a/include/linux/backlight.h >> +++ b/include/linux/backlight.h >> @@ -100,6 +100,9 @@ struct backlight_device { >> /* The framebuffer notifier block */ >> struct notifier_block fb_notif; >> >> + /* list entry of all registered backlight devices */ >> + struct list_head entry; >> + >> struct device dev; >> }; >> >> @@ -123,6 +126,7 @@ extern void devm_backlight_device_unregister(struct device *dev, >> struct backlight_device *bd); >> extern void backlight_force_update(struct backlight_device *bd, >> enum backlight_update_reason reason); >> +extern bool backlight_device_registered(enum backlight_type type); >> >> #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) > > Thanks! Thanks for the review, -Aaron
On Thursday, October 10, 2013 08:54:29 AM Aaron Lu wrote: > On 10/10/2013 08:25 AM, Rafael J. Wysocki wrote: > > On Tuesday, October 08, 2013 02:39:58 PM Aaron Lu wrote: > >> Introduce a new API for modules to query if a specific type of backlight > >> device has been registered. This is useful for some backlight device > >> provider module(e.g. ACPI video) to know if a native control > >> interface(e.g. the interface created by i915) is available and then do > >> things accordingly(e.g. avoid register its own on Win8 systems). > >> > >> Signed-off-by: Aaron Lu <aaron.lu@intel.com> > >> Tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com> > >> Tested-by: Yves-Alexis Perez <corsac@debian.org> > >> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> > >> --- > >> drivers/video/backlight/backlight.c | 31 +++++++++++++++++++++++++++++++ > >> include/linux/backlight.h | 4 ++++ > >> 2 files changed, 35 insertions(+) > >> > >> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c > >> index 94a403a..bf2d71d 100644 > >> --- a/drivers/video/backlight/backlight.c > >> +++ b/drivers/video/backlight/backlight.c > >> @@ -21,6 +21,9 @@ > >> #include <asm/backlight.h> > >> #endif > >> > >> +static struct list_head bd_list_head; > >> +static struct mutex bd_list_mutex; > > > > I'd prefer these two things to be called backlight_dev_list and > > backlight_dev_list_mutex, respectively. > > OK. > > > > >> + > >> static const char *const backlight_types[] = { > >> [BACKLIGHT_RAW] = "raw", > >> [BACKLIGHT_PLATFORM] = "platform", > >> @@ -349,10 +352,32 @@ struct backlight_device *backlight_device_register(const char *name, > >> mutex_unlock(&pmac_backlight_mutex); > >> #endif > >> > >> + mutex_lock(&bd_list_mutex); > >> + list_add(&new_bd->entry, &bd_list_head); > >> + mutex_unlock(&bd_list_mutex); > >> + > >> return new_bd; > >> } > >> EXPORT_SYMBOL(backlight_device_register); > >> > >> +bool backlight_device_registered(enum backlight_type type) > >> +{ > >> + bool found = false; > >> + struct backlight_device *bd; > >> + > >> + mutex_lock(&bd_list_mutex); > >> + list_for_each_entry(bd, &bd_list_head, entry) { > >> + if (bd->props.type == type) { > >> + found = true; > >> + break; > >> + } > >> + } > > > > Isn't it useful to be able to register more than one backlight device of the > > same type sometimes? > > I think so for some kind of computers. OTOH, the above function should > be enough for the problem we are solving here, if someday we need to > differentiate, we can enhance the code then. OK
On Thu, 10 Oct 2013, Aaron Lu <aaron.lu@intel.com> wrote: > On 10/10/2013 08:25 AM, Rafael J. Wysocki wrote: >> On Tuesday, October 08, 2013 02:39:58 PM Aaron Lu wrote: >>> +bool backlight_device_registered(enum backlight_type type) >>> +{ >>> + bool found = false; >>> + struct backlight_device *bd; >>> + >>> + mutex_lock(&bd_list_mutex); >>> + list_for_each_entry(bd, &bd_list_head, entry) { >>> + if (bd->props.type == type) { >>> + found = true; >>> + break; >>> + } >>> + } >> >> Isn't it useful to be able to register more than one backlight device of the >> same type sometimes? > > I think so for some kind of computers. OTOH, the above function should > be enough for the problem we are solving here, if someday we need to > differentiate, we can enhance the code then. Since both Baytrail and Haswell already have two backlight PWMs, this may be needed sooner than you think. But we shouldn't let that block fixing the more urgent issue we have now. So I'm fine with this. It doesn't prevent one from registering more than one device of the same type anyway. BR, Jani.
On 10/10/2013 12:29 PM, Jani Nikula wrote: > On Thu, 10 Oct 2013, Aaron Lu <aaron.lu@intel.com> wrote: >> On 10/10/2013 08:25 AM, Rafael J. Wysocki wrote: >>> On Tuesday, October 08, 2013 02:39:58 PM Aaron Lu wrote: >>>> +bool backlight_device_registered(enum backlight_type type) >>>> +{ >>>> + bool found = false; >>>> + struct backlight_device *bd; >>>> + >>>> + mutex_lock(&bd_list_mutex); >>>> + list_for_each_entry(bd, &bd_list_head, entry) { >>>> + if (bd->props.type == type) { >>>> + found = true; >>>> + break; >>>> + } >>>> + } >>> >>> Isn't it useful to be able to register more than one backlight device of the >>> same type sometimes? >> >> I think so for some kind of computers. OTOH, the above function should >> be enough for the problem we are solving here, if someday we need to >> differentiate, we can enhance the code then. > > Since both Baytrail and Haswell already have two backlight PWMs, this > may be needed sooner than you think. But we shouldn't let that block Do we need to differentiate which backlight PWM is registered to decide if ACPI video backlight interface should be skipped? My understanding is no. Thanks, Aaron > fixing the more urgent issue we have now. So I'm fine with this. It > doesn't prevent one from registering more than one device of the same > type anyway. > > BR, > Jani. > > >
On Thu, 10 Oct 2013, Aaron Lu <aaron.lu@intel.com> wrote: > On 10/10/2013 12:29 PM, Jani Nikula wrote: >> On Thu, 10 Oct 2013, Aaron Lu <aaron.lu@intel.com> wrote: >>> On 10/10/2013 08:25 AM, Rafael J. Wysocki wrote: >>>> On Tuesday, October 08, 2013 02:39:58 PM Aaron Lu wrote: >>>>> +bool backlight_device_registered(enum backlight_type type) >>>>> +{ >>>>> + bool found = false; >>>>> + struct backlight_device *bd; >>>>> + >>>>> + mutex_lock(&bd_list_mutex); >>>>> + list_for_each_entry(bd, &bd_list_head, entry) { >>>>> + if (bd->props.type == type) { >>>>> + found = true; >>>>> + break; >>>>> + } >>>>> + } >>>> >>>> Isn't it useful to be able to register more than one backlight device of the >>>> same type sometimes? >>> >>> I think so for some kind of computers. OTOH, the above function should >>> be enough for the problem we are solving here, if someday we need to >>> differentiate, we can enhance the code then. >> >> Since both Baytrail and Haswell already have two backlight PWMs, this >> may be needed sooner than you think. But we shouldn't let that block > > Do we need to differentiate which backlight PWM is registered to decide > if ACPI video backlight interface should be skipped? My understanding is > no. That's correct. If things change, we can fix it then. Jani. > > Thanks, > Aaron > >> fixing the more urgent issue we have now. So I'm fine with this. It >> doesn't prevent one from registering more than one device of the same >> type anyway. >> >> BR, >> Jani. >> >> >> >
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 94a403a..bf2d71d 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -21,6 +21,9 @@ #include <asm/backlight.h> #endif +static struct list_head bd_list_head; +static struct mutex bd_list_mutex; + static const char *const backlight_types[] = { [BACKLIGHT_RAW] = "raw", [BACKLIGHT_PLATFORM] = "platform", @@ -349,10 +352,32 @@ struct backlight_device *backlight_device_register(const char *name, mutex_unlock(&pmac_backlight_mutex); #endif + mutex_lock(&bd_list_mutex); + list_add(&new_bd->entry, &bd_list_head); + mutex_unlock(&bd_list_mutex); + return new_bd; } EXPORT_SYMBOL(backlight_device_register); +bool backlight_device_registered(enum backlight_type type) +{ + bool found = false; + struct backlight_device *bd; + + mutex_lock(&bd_list_mutex); + list_for_each_entry(bd, &bd_list_head, entry) { + if (bd->props.type == type) { + found = true; + break; + } + } + mutex_unlock(&bd_list_mutex); + + return found; +} +EXPORT_SYMBOL(backlight_device_registered); + /** * backlight_device_unregister - unregisters a backlight device object. * @bd: the backlight device object to be unregistered and freed. @@ -364,6 +389,10 @@ void backlight_device_unregister(struct backlight_device *bd) if (!bd) return; + mutex_lock(&bd_list_mutex); + list_del(&bd->entry); + mutex_unlock(&bd_list_mutex); + #ifdef CONFIG_PMAC_BACKLIGHT mutex_lock(&pmac_backlight_mutex); if (pmac_backlight == bd) @@ -499,6 +528,8 @@ static int __init backlight_class_init(void) backlight_class->dev_groups = bl_device_groups; backlight_class->pm = &backlight_class_dev_pm_ops; + INIT_LIST_HEAD(&bd_list_head); + mutex_init(&bd_list_mutex); return 0; } diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 53b7794..5f9cd96 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -100,6 +100,9 @@ struct backlight_device { /* The framebuffer notifier block */ struct notifier_block fb_notif; + /* list entry of all registered backlight devices */ + struct list_head entry; + struct device dev; }; @@ -123,6 +126,7 @@ extern void devm_backlight_device_unregister(struct device *dev, struct backlight_device *bd); extern void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason); +extern bool backlight_device_registered(enum backlight_type type); #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)