Re: [PATCH V4 8/8] backlight: qcom-wled: Add auto string detection logic

From: Bjorn Andersson
Date: Tue Aug 07 2018 - 02:29:15 EST


On Mon 09 Jul 03:22 PDT 2018, Kiran Gunda wrote:
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
[..]
> @@ -189,6 +206,15 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
> return 0;
> }
>
> +static void wled_ovp_work(struct work_struct *work)
> +{
> + struct wled *wled = container_of(work,
> + struct wled, ovp_work.work);
> +
> + if (wled->ovp_irq > 0)
> + enable_irq(wled->ovp_irq);
> +}
> +
> static int wled_module_enable(struct wled *wled, int val)
> {
> int rc;
> @@ -200,7 +226,18 @@ static int wled_module_enable(struct wled *wled, int val)
> WLED_CTRL_REG_MOD_EN,
> WLED_CTRL_REG_MOD_EN_MASK,
> val << WLED_CTRL_REG_MOD_EN_SHIFT);
> - return rc;
> + if (rc < 0)
> + return rc;
> +
> + if (val) {
> + schedule_delayed_work(&wled->ovp_work, WLED_SOFT_START_DLY_US);

schedule_delayed_work() takes a delay in jiffies, not micro seconds.

> + } else {
> + cancel_delayed_work_sync(&wled->ovp_work);

If we get here within WLED_SOFT_START_DLY_US of a module enable we have
yet to execute the enable_irq() in the delayed worker, which should mean
that the irq is unbalanced from then on.

I believe you can check the return value of cancel_delayed_work_sync()
being true to know if wled_ovp_work() was yet to execute.

> + if (wled->ovp_irq > 0)
> + disable_irq(wled->ovp_irq);
> + }
> +
> + return 0;
> }
>

Regards,
Bjorn