Subject: Re: [PATCH] leds: mt6360: Fix the second LED can not enable torch mode by V4L2

Il 09/04/24 12:21, ChiaEn Wu ha scritto:
> V4L2 will disable strobe mode of the LED device when enable torch mode,
> but this logic will conflict with the "priv->fled_torch_used"
> in "mt6360_strobe_set()". So after enabling torch mode of the first
> LED, the second LED will not be able to enable torch mode correctly.
>
> Therefore, at the beginning of "mt6360_strobe_set()", check whether the
> state of the upcoming change and the current LED device state are the
> same, so as to avoid the above problem.
>
> Signed-off-by: ChiaEn Wu <[email protected]>
> ---
> drivers/leds/flash/leds-mt6360.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/leds/flash/leds-mt6360.c b/drivers/leds/flash/leds-mt6360.c
> index a90de82f4568..1b75b4d36834 100644
> --- a/drivers/leds/flash/leds-mt6360.c
> +++ b/drivers/leds/flash/leds-mt6360.c
> @@ -241,10 +241,20 @@ static int mt6360_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
> u32 enable_mask = MT6360_STROBEN_MASK | MT6360_FLCSEN_MASK(led->led_no);
> u32 val = state ? MT6360_FLCSEN_MASK(led->led_no) : 0;
> u32 prev = priv->fled_strobe_used, curr;
> - int ret;
> + int ret = 0;

I prefer that you leave ret uninitialized here, and...

>
> mutex_lock(&priv->lock);
>
> + /*
> + * If the state of the upcoming change is the same as the current LED
> + * device state, then skip the subsequent code to avoid conflict
> + * with the flow of turning on LED torch mode in V4L2.
> + */
> + if (state == !!(BIT(led->led_no) & prev)) {
> + dev_info(lcdev->dev, "No change in strobe state [0x%x]\n", prev);

..that you do here, instead

ret = 0;
goto unlock;

With that addressed,

Reviewed-by: AngeloGioacchino Del Regno <[email protected]>




2024-04-11 06:55:24

by Lee Jones

[permalink] [raw]
Subject: Re: [PATCH] leds: mt6360: Fix the second LED can not enable torch mode by V4L2

On Tue, 09 Apr 2024, AngeloGioacchino Del Regno wrote:

Not sure why, but this mail was sent unthreaded from the original.

> Il 09/04/24 12:21, ChiaEn Wu ha scritto:
> > V4L2 will disable strobe mode of the LED device when enable torch mode,
> > but this logic will conflict with the "priv->fled_torch_used"
> > in "mt6360_strobe_set()". So after enabling torch mode of the first
> > LED, the second LED will not be able to enable torch mode correctly.
> >
> > Therefore, at the beginning of "mt6360_strobe_set()", check whether the
> > state of the upcoming change and the current LED device state are the
> > same, so as to avoid the above problem.
> >
> > Signed-off-by: ChiaEn Wu <[email protected]>
> > ---
> > drivers/leds/flash/leds-mt6360.c | 12 +++++++++++-
> > 1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/leds/flash/leds-mt6360.c b/drivers/leds/flash/leds-mt6360.c
> > index a90de82f4568..1b75b4d36834 100644
> > --- a/drivers/leds/flash/leds-mt6360.c
> > +++ b/drivers/leds/flash/leds-mt6360.c
> > @@ -241,10 +241,20 @@ static int mt6360_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
> > u32 enable_mask = MT6360_STROBEN_MASK | MT6360_FLCSEN_MASK(led->led_no);
> > u32 val = state ? MT6360_FLCSEN_MASK(led->led_no) : 0;
> > u32 prev = priv->fled_strobe_used, curr;
> > - int ret;
> > + int ret = 0;
>
> I prefer that you leave ret uninitialized here, and...

What's the reason for this?

> > mutex_lock(&priv->lock);
> > + /*
> > + * If the state of the upcoming change is the same as the current LED
> > + * device state, then skip the subsequent code to avoid conflict
> > + * with the flow of turning on LED torch mode in V4L2.
> > + */
> > + if (state == !!(BIT(led->led_no) & prev)) {
> > + dev_info(lcdev->dev, "No change in strobe state [0x%x]\n", prev);
>
> ...that you do here, instead
>
> ret = 0;
> goto unlock;
>
> With that addressed,
>
> Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
>
>

--
Lee Jones [李琼斯]