[{"id":3688365,"web_url":"http://patchwork.ozlabs.org/comment/3688365/","msgid":"<6cf43fb7-f39a-437e-bcdb-23a4d20d2b10@mailbox.org>","list_archive_url":null,"date":"2026-05-08T11:49:28","subject":"Re: [PATCH RESEND] watchdog: sbsa_gwdt: clamp WOR value to hw max","submitter":{"id":69987,"url":"http://patchwork.ozlabs.org/api/people/69987/","name":"Stefan Roese","email":"stefan.roese@mailbox.org"},"content":"On 5/4/26 11:34, Juuso Rinta wrote:\n> The WOR register is 32 bits, so any tick count exceeding U32_MAX is\n> truncated by writel(). A large requested timeout can wrap to a small\n> value causing the watchdog to fire sooner than requested.\n> \n> Clamp the calculated value to U32_MAX prior to writing the register so\n> over-large requests will be set to the maximum timeout value.\n> \n> Found by code review.\n> \n> Signed-off-by: Juuso Rinta \n\nReviewed-by: Stefan Roese \n\nThanks,\nStefan\n\n\n> ---\n> drivers/watchdog/sbsa_gwdt.c | 10 ++++++++--\n> 1 file changed, 8 insertions(+), 2 deletions(-)\n> \n> diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c\n> index 807884c5bc7..3a924cb2b9a 100644\n> --- a/drivers/watchdog/sbsa_gwdt.c\n> +++ b/drivers/watchdog/sbsa_gwdt.c\n> @@ -50,6 +50,7 @@ static int sbsa_gwdt_start(struct udevice *dev, u64 timeout, ulong flags)\n> {\n> \tstruct sbsa_gwdt_priv *priv = dev_get_priv(dev);\n> \tu32 clk;\n> +\tu64 tout_wdog;\n> \n> \t/*\n> \t * it work in the single stage mode in u-boot,\n> @@ -58,8 +59,13 @@ static int sbsa_gwdt_start(struct udevice *dev, u64 timeout, ulong flags)\n> \t * to half value of timeout.\n> \t */\n> \tclk = get_tbclk();\n> -\twritel(clk / (2 * 1000) * timeout,\n> -\t priv->reg_control + SBSA_GWDT_WOR);\n> +\n> +\t/* if requested timeout overflows, clamp it to u32_max */\n> +\ttout_wdog = ((u64)clk * timeout) / (2 * 1000);\n> +\tif (tout_wdog > U32_MAX)\n> +\t\ttout_wdog = U32_MAX;\n> +\n> +\twritel(tout_wdog, priv->reg_control + SBSA_GWDT_WOR);\n> \n> \t/* writing WCS will cause an explicit watchdog refresh */\n> \twritel(SBSA_GWDT_WCS_EN, priv->reg_control + SBSA_GWDT_WCS);\n> \n> ---\n> base-commit: 4433253ecf2041f9362a763bb6cb79960921ac7e\n> change-id: 20260428-fix-sbsa-timeout-overflow-20cf84fa8a6b\n> \n> Best regards,\n> --\n> Juuso Rinta ","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=mailbox.org header.i=@mailbox.org header.a=rsa-sha256\n header.s=mail20150812 header.b=q6Trd1C/;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de\n (client-ip=2a01:238:438b:c500:173d:9f52:ddab:ee01; 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