Added a check to ensure the requested timeout does not exceed the hardware's maximum supported value. This prevents register overflow and ensures watchdog reliability.
So, added a check in qcom_wdt_start() to ensure the requested timeout does not exceed the hardware-supported maximum value. The timeout is first converted to watchdog ticks and then compared against QCOM_WDT_MAX_TIMEOUT. This helps prevent misconfiguration and potential watchdog misbehavior due to overflow. QCOM_WDT_MAX_TIMEOUT is set to 0xFFFFF, as Qualcomm SoCs typically use 20 bits to store bark/bite timeout values. This work builds upon the previous submission: https://lore.kernel.org/u-boot/[email protected]/ Signed-off-by: Gopinath Sekar <[email protected]> --- drivers/watchdog/qcom-wdt.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index adbb5aacdc3..eeeea4c24b7 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -17,6 +17,9 @@ #include <asm/io.h> +/* Maximum allowed timeout value in Qcom SoCs*/ +#define QCOM_WDT_MAX_TIMEOUT 0xfffff + enum wdt_reg { WDT_RST, WDT_EN, @@ -55,8 +58,20 @@ static void __iomem *wdt_addr(struct qcom_wdt *wdt, enum wdt_reg reg) int qcom_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags) { struct qcom_wdt *wdt = dev_get_priv(dev); - ulong bark_timeout_s = ((timeout_ms - 1) * wdt->clk_rate) / 1000; - ulong bite_timeout_s = (timeout_ms * wdt->clk_rate) / 1000; + u64 tmp_timeout; + u32 bark_timeout_s, bite_timeout_s; + + /* Compute timeout in watchdog ticks */ + tmp_timeout = (timeout_ms * (u64)wdt->clk_rate) / 1000; + if (tmp_timeout > QCOM_WDT_MAX_TIMEOUT) { + dev_err(dev, "Requested timeout (%llu ms) exceeds maximum allowed value (%llu ms).\n", + timeout_ms, ((u64)QCOM_WDT_MAX_TIMEOUT * 1000) / wdt->clk_rate); + return -EINVAL; + } + bite_timeout_s = (u32)tmp_timeout; + + tmp_timeout = ((timeout_ms - 1) * (u64)wdt->clk_rate) / 1000; + bark_timeout_s = (u32)tmp_timeout; writel(0, wdt_addr(wdt, WDT_EN)); writel(BIT(0), wdt_addr(wdt, WDT_RST)); -- 2.34.1
