[PATCH v1] watchdog: qcom-wdt: Drop read check on write-only WDT_EN register
Balaji Selvanathan
balaji.selvanathan at oss.qualcomm.com
Tue Jul 1 08:57:38 CEST 2025
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 <balaji.selvanathan at oss.qualcomm.com>
---
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 af97b27e311..e4ebb1f31d4 100644
--- a/drivers/watchdog/qcom-wdt.c
+++ b/drivers/watchdog/qcom-wdt.c
@@ -82,10 +82,7 @@ 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;
}
--
2.34.1
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