From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99BC23E00A3; Wed, 30 Sep 2026 19:27:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796429; cv=none; b=Ax3/U1Y/nIN0bCm9W4Y8639yXMWrSy73BiNBs7OYcUssA+AVMVXVFSaDAY+COsZ7wLCxz+FzpDVIxlJWoXrSDnq1eZNk97kWXEtM/aUXxI3ma7Peu4Hj3niBEuUlHgRPwx4yYcv1MaRNZRZRy2JYeZv0zJF29/Rdp95fHw7UsrI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796429; c=relaxed/simple; bh=F8+tS9WT6VGuDAMjX2t6Pzf8WifC0wwrklX0gYY+1+A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MZE28Ha5Ooa0M7hB5ejGUcg30c7+UJTHUmMAeXlYjrrVKjpunKY7Gt4ktDvw0gyZiKV9M9e2Six93R106/1s8Y8RBmgNqupCBkU+Gtf78aDBIUPBN4nDHvpVZh2o5qyCNAIas88bW5a66LoLOnqXVDTAhIw6RD9OOyMJE29HkJE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kAeq/itL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kAeq/itL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 012A01F000FF; Wed, 30 Sep 2026 19:27:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796428; bh=KRDV3FXdfXYjKotJDz7ai6aMOCJoY1+DcGKO0b5iUw0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kAeq/itLTervNsXDhPDfzl1bkkjywWB337oxAsF5oKHMTzehlY8UgtMV/CRb5arLv SpSihpSdJrckFj9G0TfX7zjqpSS9T+Jr3FPxvgeX1rbUZFyVSgQQsyHWwsvnTWmzg7 oIErSgAUDrcMU8i1KhXAf7JkgCV9p9ZBfMo79V1Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tzung-Bi Shih , Baruch Siach , Guenter Roeck Subject: [PATCH 6.6 0911/1193] watchdog: digicolor: Avoid division by zero Date: Wed, 30 Sep 2026 17:26:35 +0200 Message-ID: <20260930152454.482109315@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tzung-Bi Shih commit 400cb663ca019bae6eb878f06f1094ddf7c0b0df upstream. clk_get_rate() could return 0. Avoid a division by zero panic. Since get_timeleft() cannot propagate errors, check the clock rate early in probe() and cache the rate in the driver data as it is unlikely to change at runtime. Fixes: 336694a01dae ("watchdog: digicolor: driver for Conexant Digicolor CX92755 SoC") Cc: stable@vger.kernel.org Signed-off-by: Tzung-Bi Shih Acked-by: Baruch Siach Link: https://patch.msgid.link/20260913064851.8239-2-tzungbi@kernel.org Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/watchdog/digicolor_wdt.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/watchdog/digicolor_wdt.c +++ b/drivers/watchdog/digicolor_wdt.c @@ -25,6 +25,7 @@ struct dc_wdt { void __iomem *base; struct clk *clk; spinlock_t lock; + unsigned long rate; }; static unsigned timeout; @@ -61,7 +62,7 @@ static int dc_wdt_start(struct watchdog_ { struct dc_wdt *wdt = watchdog_get_drvdata(wdog); - dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk)); + dc_wdt_set(wdt, wdog->timeout * wdt->rate); return 0; } @@ -79,7 +80,7 @@ static int dc_wdt_set_timeout(struct wat { struct dc_wdt *wdt = watchdog_get_drvdata(wdog); - dc_wdt_set(wdt, t * clk_get_rate(wdt->clk)); + dc_wdt_set(wdt, t * wdt->rate); wdog->timeout = t; return 0; @@ -90,7 +91,7 @@ static unsigned int dc_wdt_get_timeleft( struct dc_wdt *wdt = watchdog_get_drvdata(wdog); uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT); - return count / clk_get_rate(wdt->clk); + return count / wdt->rate; } static const struct watchdog_ops dc_wdt_ops = { @@ -130,7 +131,11 @@ static int dc_wdt_probe(struct platform_ wdt->clk = devm_clk_get(dev, NULL); if (IS_ERR(wdt->clk)) return PTR_ERR(wdt->clk); - dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk); + + wdt->rate = clk_get_rate(wdt->clk); + if (!wdt->rate) + return -EINVAL; + dc_wdt_wdd.max_timeout = U32_MAX / wdt->rate; dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout; dc_wdt_wdd.parent = dev;