Re: [PATCH v3 04/10] leds: core: Use set_brightness_work for the blocking op

[Jacek Anaszewski]

Hi Sakari,

Thanks for the review.

On 10/16/2015 05:43 PM, Sakari Ailus wrote:
> Hi Jacek,
>
> I think I'd rearrange patches 3 and 4; delayed_set_brightness is briefly
> needed in patch 3 but again no longer here.

The impression that delayed_set_brightness is not needed is caused
by my mistake in set_brightness_delayed(), please see my explanation
below.

> I have to say I quite like the set, it cleans up the framework a lot.
> Thanks!
>
> On Wed, Oct 07, 2015 at 11:10:42AM +0200, Jacek Anaszewski wrote:
> > This patch makes LED core capable of setting brightness for drivers
> > that implement brightness_set_blocking op. It removes from LED class
> > drivers responsibility for using work queues on their own.
> >
> > In order to achieve this set_brightness_delayed callback is being
> > modified to directly call one of available ops for brightness setting.
> >
> > led_set_brightness_async() function didn't set brightness in an
> > asynchronous way in all cases. It was mistakenly assuming that all
> > LED subsystem drivers used work queue in their brightness_set op,
> > whereas only half of them did that. Since it has no users now,
> > it is being removed.
> >
> > Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> > ---
> >   drivers/leds/led-core.c |   12 +++++++++++-
> >   drivers/leds/leds.h     |   10 ----------
> >   include/linux/leds.h    |    2 +-
> >   3 files changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
> > index a1f53aa..7d2512f 100644
> > --- a/drivers/leds/led-core.c
> > +++ b/drivers/leds/led-core.c
> > @@ -83,6 +83,7 @@ static void set_brightness_delayed(struct work_struct *ws)
> >   {
> >   	struct led_classdev *led_cdev =
> >   		container_of(ws, struct led_classdev, set_brightness_work);
> > +	int ret = 0;
> >
> >   	if (led_cdev->flags & LED_BLINK_DISABLE) {
> >   		led_cdev->delayed_set_value = LED_OFF;
> > @@ -90,7 +91,16 @@ static void set_brightness_delayed(struct work_struct *ws)
> >   		led_cdev->flags &= ~LED_BLINK_DISABLE;
> >   	}
> >
> > -	led_set_brightness_async(led_cdev, led_cdev->delayed_set_value);
> > +	if (led_cdev->brightness_set)
> > +		led_cdev->brightness_set(led_cdev, led_cdev->brightness);

s/led_cdev->brightness/led_cdev->delayed_set_value/

> > +	else if (led_cdev->brightness_set_blocking)
> > +		ret = led_cdev->brightness_set_blocking(led_cdev,
> > +							led_cdev->brightness);

s/led_cdev->brightness/led_cdev->delayed_set_value/

led_set_brightness_nopm() wouldn't have effect if we relied here on
led_cdev->brightness. The former, being called from
led_classdev_suspend(), turns the LED off, but without overwriting
led_cdev->brightness, so that led_classdev_resume could restore it.

I will submit the fixed set soon.

--
Best Regards,
Jacek Anaszewski
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