Messages in this thread | | | Date | Wed, 18 May 2016 16:34:56 +0200 | From | Jacek Anaszewski <> | Subject | Re: [PATCH] Let chip-driver set brightness if, software blink not used. |
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On 05/18/2016 12:33 PM, Tony Makkiel wrote: > > > On 18/05/16 10:03, Jacek Anaszewski wrote: >> Hi Tony, >> >> Thanks for the patch. I'd like to improve the commit message. >> >> Please let me know if you have any suggestions related to the below: >> >> led: core: Fix brightness setting upon hardware blinking enabled >> >> Commit 76931edd54 ('leds: fix brightness changing when software blinking >> is active') changed the semantics of led_set_brightness() which according >> to the documentation should disable blinking on any brightness setting. >> Moreover it made it different for soft blink case, where it was allowed >> for blink brightness change, and for hardware blink case, where setting >> any brightness greater than 0 was ignored. >> >> While the change itself is against the documentation claims, it was driven >> also by the fact that timer trigger remained active after turning blinking >> off. Fixing that would have required major refactoring in the led-core, >> led-class, and led-triggers because of cyclic dependencies. >> >> Finally, it has been decided that allowing for brightness change during >> blinking is beneficial as it can be accomplished without disturbing >> blink rhythm. >> >> The change in brightness setting semantics will not affect existing >> LED class drivers that implement blink_set op thanks to the LED_BLINK_SW >> flag introduced by this patch. The flag state will be from now on checked >> in led_set_brightness() which will allow to distinguish between hardware >> and software blink mode. In the former case the control will be passed >> directly to the drivers which apply their semantics on brightness set, >> which is disable the blinking in case of most such drivers. New drivers >> will apply new semantics and just change the brightness while hardware >> blinking is on, if possible. >> >> Due to the later LED core improvements this patch can't be applied directly >> on the patch that originally introduced the problem, but to the later one, >> that touched the affected code. >> >> Fixes: f1e80c07416a ("leds: core: Add two new LED_BLINK_ flags") >> Signed-off-by: Tony Makkiel <tony.makkiel@daqri.com> >> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> >> >> > It looks good to me. Do you want me to resubmit the patch with new commit message? > Or can you edit it while merging the patch.
Yes please, if it's not a problem.
>> We will need also to modify the documentation, but this can >> be done in a separate patch. > > Will make another patch for it. Does the following look ok? > > diff --git a/Documentation/leds/leds-class.txt b/Documentation/leds/leds-class.txt > index d406d98..44f5e6b 100644 > --- a/Documentation/leds/leds-class.txt > +++ b/Documentation/leds/leds-class.txt > @@ -74,8 +74,8 @@ blink_set() function (see <linux/leds.h>). To set an LED to blinking, > however, it is better to use the API function led_blink_set(), as it > will check and implement software fallback if necessary. > > -To turn off blinking again, use the API function led_brightness_set() > -as that will not just set the LED brightness but also stop any software > +To turn off blinking, use the API function led_brightness_set() > +with brightness value LED_OFF, which should stop any software > timers that may have been required for blinking.
Seems good.
> The blink_set() function should choose a user friendly blinking value > >> >> On 05/17/2016 06:28 PM, Tony Makkiel wrote: >>> With this patch, chip drivers will be given option to >>> set brightness while, blink is active. >>> >>> Signed-off-by: Tony Makkiel <tony.makkiel@daqri.com> >>> --- >>> drivers/leds/led-core.c | 7 +++++-- >>> include/linux/leds.h | 19 ++++++++++--------- >>> 2 files changed, 15 insertions(+), 11 deletions(-) >>> >>> diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c >>> index 3495d5d..b595eb9 100644 >>> --- a/drivers/leds/led-core.c >>> +++ b/drivers/leds/led-core.c >>> @@ -53,11 +53,12 @@ static void led_timer_function(unsigned long data) >>> >>> if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { >>> led_set_brightness_nosleep(led_cdev, LED_OFF); >>> + led_cdev->flags &= ~LED_BLINK_SW; >>> return; >>> } >>> >>> if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) { >>> - led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; >>> + led_cdev->flags &= ~(LED_BLINK_ONESHOT_STOP | LED_BLINK_SW); >>> return; >>> } >>> >>> @@ -151,6 +152,7 @@ static void led_set_software_blink(struct led_classdev *led_cdev, >>> return; >>> } >>> >>> + led_cdev->flags |= LED_BLINK_SW; >>> mod_timer(&led_cdev->blink_timer, jiffies + 1); >>> } >>> >>> @@ -219,6 +221,7 @@ void led_stop_software_blink(struct led_classdev *led_cdev) >>> del_timer_sync(&led_cdev->blink_timer); >>> led_cdev->blink_delay_on = 0; >>> led_cdev->blink_delay_off = 0; >>> + led_cdev->flags &= ~LED_BLINK_SW; >>> } >>> EXPORT_SYMBOL_GPL(led_stop_software_blink); >>> >>> @@ -229,7 +232,7 @@ void led_set_brightness(struct led_classdev *led_cdev, >>> * In case blinking is on delay brightness setting >> >> We need to make this comment more precise: > > Will include the following along with documentation patch, unless require modification. > > diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c > index b595eb9..f3af7a6 100644 > --- a/drivers/leds/led-core.c > +++ b/drivers/leds/led-core.c > @@ -229,7 +229,7 @@ void led_set_brightness(struct led_classdev *led_cdev, > enum led_brightness brightness) > { > /* > - * In case blinking is on delay brightness setting > + * If software blink active, delay brightness setting
s/active/is active/
> * until the next timer tick. > */ > if (led_cdev->flags & LED_BLINK_SW) { > >> >> s/blinking/soft blink/g >> >>> * until the next timer tick. >>> */ >>> - if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) { >>> + if (led_cdev->flags & LED_BLINK_SW) { >>> /* >>> * If we need to disable soft blinking delegate this to the >>> * work queue task to avoid problems in case we are called >>> diff --git a/include/linux/leds.h b/include/linux/leds.h >>> index d2b1306..99b1f0b 100644 >>> --- a/include/linux/leds.h >>> +++ b/include/linux/leds.h >>> @@ -42,15 +42,16 @@ struct led_classdev { >>> #define LED_UNREGISTERING (1 << 1) >>> /* Upper 16 bits reflect control information */ >>> #define LED_CORE_SUSPENDRESUME (1 << 16) >>> -#define LED_BLINK_ONESHOT (1 << 17) >>> -#define LED_BLINK_ONESHOT_STOP (1 << 18) >>> -#define LED_BLINK_INVERT (1 << 19) >>> -#define LED_BLINK_BRIGHTNESS_CHANGE (1 << 20) >>> -#define LED_BLINK_DISABLE (1 << 21) >>> -#define LED_SYSFS_DISABLE (1 << 22) >>> -#define LED_DEV_CAP_FLASH (1 << 23) >>> -#define LED_HW_PLUGGABLE (1 << 24) >>> -#define LED_PANIC_INDICATOR (1 << 25) >>> +#define LED_BLINK_SW (1 << 17) >>> +#define LED_BLINK_ONESHOT (1 << 18) >>> +#define LED_BLINK_ONESHOT_STOP (1 << 19) >>> +#define LED_BLINK_INVERT (1 << 20) >>> +#define LED_BLINK_BRIGHTNESS_CHANGE (1 << 21) >>> +#define LED_BLINK_DISABLE (1 << 22) >>> +#define LED_SYSFS_DISABLE (1 << 23) >>> +#define LED_DEV_CAP_FLASH (1 << 24) >>> +#define LED_HW_PLUGGABLE (1 << 25) >>> +#define LED_PANIC_INDICATOR (1 << 26) >>> >>> /* Set LED brightness level >>> * Must not sleep. Use brightness_set_blocking for drivers >>> >> >> > >
-- Best regards, Jacek Anaszewski
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