Re: [PATCH V5 8/8] backlight: qcom-wled: Add auto string detection logic

From: Bjorn Andersson
Date: Mon Aug 27 2018 - 10:50:44 EST


On Fri 24 Aug 03:27 PDT 2018, Kiran Gunda wrote:
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
[..]
> struct wled {
> @@ -135,16 +146,22 @@ struct wled {
> struct regmap *regmap;
> struct mutex lock; /* Lock to avoid race from thread irq handler */
> ktime_t last_short_event;
> + ktime_t start_ovp_fault_time;
> u16 ctrl_addr;
> u16 sink_addr;
> u16 max_string_count;
> + u16 auto_detection_ovp_count;
> u32 brightness;
> u32 max_brightness;
> u32 short_count;
> + u32 auto_detect_count;
> bool disabled_by_short;
> bool has_short_detect;
> + int ovp_irq;
> + bool ovp_irq_disabled;

ovp_irq_disabled is now only assigned, never read. So you should be able
to drop it.

[..]
> @@ -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, HZ / 100);

wled_ovp_work() is a nop when ovp_irq == 0, so wrap the entire if/else
in a check for ovp_irq > 0 (rather than include it in the else) and drop
it from the worker.

> + } else {
> + if (!cancel_delayed_work_sync(&wled->ovp_work) &&
> + wled->ovp_irq > 0)
> + disable_irq(wled->ovp_irq);
> + }
> +
> + return 0;

Also, if a user calls rmmod within 10ms of enabling module we will
schedule work of code that's no longer available in the kernel. So you
need to also cancel_delayed_work_sync() in the remove function of the
driver.


Apart from this I think this patch looks good now!

Regards,
Bjorn