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 E9FDF53B5EE; Wed, 23 Sep 2026 14:51:49 +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=1790175111; cv=none; b=C172EcJdqOBwJiFpFzCr3C84ruCH3cPfbSRXl5q9ZF/pu+pRZiZJpWU14D5ZTcGWdJtxhKzFB8Ji+ryK8KdeyFh460rsLVC1A+u4YQgmBAGVs1CBE++5paLqYLCGdjxtXJHbquMfL6RJI+7WGCbphNd+vYtQ41BJFQ1z4HVQtC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790175111; c=relaxed/simple; bh=r9Rzyl0xL4bUbKGsdNEiupf5YdaCHnPn0Rjj1vd2NMA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VmUgj1R70ySU1zX/0Cu6fmR6lJjVSW37ChY4c+iGZuDBx0ws2cLnesiMBQLJiRH+gaZsDFIK9M4BbydkSr6YkZnfZi9PpHv9HwY59oAJyJt64QXWto3Z6ZaBftyIsanRpV8HLa/2b9Ubvoh3QCkmZ6dIfng8I4TV3R06np3/LDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=svUyqjog; 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="svUyqjog" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C6781F000FF; Wed, 23 Sep 2026 14:51:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790175109; bh=vrEl5jlKWuF0XKJSMsnUlFcjT/jpB82DoocaWw6ZodU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=svUyqjog/N7RZOBzjKICVAbI62OvyhSbnx9Cf973UFb6qEcV67BOZL0P9E8nK5YPO hGtdEoGnD1nYoyuC7WnqqHOClrt2X8uIkHFXGO0kiZ1HpSyFDZVlH2B8PVN6nKMdrL 2if2CbqJGr6X9SLRSLuWz6DF9FdcCy7V5CWKppSs= 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 6.18 316/398] watchdog: digicolor: Avoid division by zero Date: Wed, 23 Sep 2026 16:06:30 +0200 Message-ID: <20260923140651.613199757@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-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;