From 9cd3118e4aa693caed6ee3fe8ef1e0b91f004484 Mon Sep 17 00:00:00 2001 From: Balaji Selvanathan Date: Tue, 1 Jul 2025 12:27:38 +0530 Subject: [PATCH] watchdog: qcom-wdt: Drop read check on write-only WDT_EN register On some Qualcomm platforms, such as Dragonwing boards, the WDT_EN register is write-only. Reading it back after enabling the watchdog can return invalid data or cause unexpected behavior. In particular, the check: if (readl(wdt_addr(wdt, WDT_EN)) != 1) may fail even though the watchdog is correctly enabled and running. This leads to misleading error messages and unnecessary failures. Removing the read check ensures compatibility and avoids false negatives on platforms where WDT_EN is not readable. This work builds upon this previous submission: https://lore.kernel.org/u-boot/20250625094607.1348494-1-gopinath.sekar@oss.qualcomm.com/ Signed-off-by: Balaji Selvanathan Reviewed-by: Stefan Roese Link: https://lore.kernel.org/r/20250701065738.1644669-1-balaji.selvanathan@oss.qualcomm.com Signed-off-by: Casey Connolly --- drivers/watchdog/qcom-wdt.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index adbb5aacdc3..4b972cff72c 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -63,10 +63,7 @@ int qcom_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) writel(bark_timeout_s, wdt_addr(wdt, WDT_BARK_TIME)); writel(bite_timeout_s, wdt_addr(wdt, WDT_BITE_TIME)); writel(BIT(0), wdt_addr(wdt, WDT_EN)); - if (readl(wdt_addr(wdt, WDT_EN)) != 1) { - dev_err(dev, "Failed to enable Qualcomm watchdog!\n"); - return -EIO; - } + return 0; } -- 2.47.2