From 22672f81f0724cbabb272fd0228fa424d4306082 Mon Sep 17 00:00:00 2001 From: David Heidelberg Date: Mon, 21 Sep 2026 12:46:23 +0200 Subject: [PATCH] backlight: qcom-wled: Fix WLED3 brightness register stride WLED3 has a 16-bit brightness register pair per string, at 0x40 + 2*n, which is what the pm8941-wled driver wrote to: rc = regmap_bulk_write(wled->regmap, wled->addr + WLED3_CTRL_REG_VAL_BASE + 2 * i, v, 2); The restructuring for WLED3 turned that into WLED3_SINK_REG_BRIGHT(n), defined as 0x40 + n, so the two byte writes for consecutive strings overlap: string 1 overwrites the MSB of string 0 with its own LSB, and with the default three strings only string 1 ends up with the requested value. Use the 2 byte stride. Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: David Heidelberg Reviewed-by: Daniel Thompson (RISCstar) Reviewed-by: Konrad Dybcio Link: https://patch.msgid.link/20260921-qcom-wled-backlight-v4-2-bab8c7ef73cb@ixit.cz Signed-off-by: Lee Jones --- drivers/video/backlight/qcom-wled.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c index 2281007bdd45..f452d328997a 100644 --- a/drivers/video/backlight/qcom-wled.c +++ b/drivers/video/backlight/qcom-wled.c @@ -59,7 +59,7 @@ #define WLED3_SINK_REG_CURR_SINK_SHFT 5 /* WLED3 specific per-'string' registers below */ -#define WLED3_SINK_REG_BRIGHT(n) (0x40 + n) +#define WLED3_SINK_REG_BRIGHT(n) (0x40 + (n * 0x2)) #define WLED3_SINK_REG_STR_MOD_EN(n) (0x60 + (n * 0x10)) #define WLED3_SINK_REG_STR_MOD_MASK BIT(7)