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

From: ChiaEn Wu
Date: Wed Apr 10 2024 - 21:32:26 EST


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 <chiaen_wu@xxxxxxxxxxx>
---
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;

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);
+ goto unlock;
+ }
+
/*
* Only one set of flash control logic, use the flag to avoid torch is
* currently used
--
2.42.0