[PATCH 04/10] leds: st1202: fix pattern_clear to explicitly mark unused slots as skip

[Manuel Fombuena <fombuena@outlook.com>]

pattern_clear used st1202_duration_pattern_write() with the minimum
duration (22 ms) to reset the eight pattern slots. With the old buggy
formula (value / 22 - 1) this accidentally wrote register value 0,
which the hardware interprets as skip. The corrected formula
(value / 22) maps 22 ms to register 1, a valid 22 ms duration.

As a result, any pattern_set() call with fewer than eight steps left
the remaining slots with 22 ms valid durations and zero PWM, making
the LED appear off for 7 x 22 ms out of every cycle.

Write 0 directly to the duration registers so that unused slots are
always explicitly marked as skip, independently of the conversion
formula.

Fixes: 259230378c65 ("leds: Add LED1202 I2C driver")
Signed-off-by: Manuel Fombuena <fombuena@outlook.com>
Assisted-by: Claude:claude-sonnet-4-6
---
 drivers/leds/leds-st1202.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/leds-st1202.c b/drivers/leds/leds-st1202.c
index 02db1006fb53..1ca77fbe4ec9 100644
--- a/drivers/leds/leds-st1202.c
+++ b/drivers/leds/leds-st1202.c
@@ -209,7 +209,7 @@ static int st1202_led_pattern_clear(struct led_classdev *ldev)
 		if (ret != 0)
 			return ret;
 
-		ret = st1202_duration_pattern_write(chip, patt, ST1202_MILLIS_PATTERN_DUR_MIN);
+		ret = st1202_write_reg(chip, ST1202_PATTERN_DUR + patt, 0);
 		if (ret != 0)
 			return ret;
 	}
-- 
2.54.0