Subject: FAILED: patch "[PATCH] watchdog: rtd119x: Avoid division by zero" failed to apply to 6.1-stable tree
To: tzungbi@kernel.org,linux@roeck-us.net
Cc: <stable@vger.kernel.org>
From: <gregkh@linuxfoundation.org>
Date: Tue, 22 Sep 2026 16:57:29 +0200
Message-ID: <2026092229-endowment-helpless-158e@gregkh>
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The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 5af7d2cbd20f893def03c8310a460ade66a5d822
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026092229-endowment-helpless-158e@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:


thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5af7d2cbd20f893def03c8310a460ade66a5d822 Mon Sep 17 00:00:00 2001
From: Tzung-Bi Shih <tzungbi@kernel.org>
Date: Sun, 13 Sep 2026 14:48:50 +0800
Subject: [PATCH] watchdog: rtd119x: Avoid division by zero

clk_get_rate() could return 0.  Avoid a division by zero panic.

Fixes: 2bdf6acbfead ("watchdog: Add Realtek RTD1295")
Cc: stable@vger.kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260913064851.8239-3-tzungbi@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/watchdog/rtd119x_wdt.c b/drivers/watchdog/rtd119x_wdt.c
index 984905695dde..0bfadb58917b 100644
--- a/drivers/watchdog/rtd119x_wdt.c
+++ b/drivers/watchdog/rtd119x_wdt.c
@@ -98,6 +98,7 @@ static int rtd119x_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rtd119x_watchdog_device *data;
+	unsigned long rate;
 
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
@@ -111,10 +112,14 @@ static int rtd119x_wdt_probe(struct platform_device *pdev)
 	if (IS_ERR(data->clk))
 		return PTR_ERR(data->clk);
 
+	rate = clk_get_rate(data->clk);
+	if (!rate)
+		return -EINVAL;
+
 	data->wdt_dev.info = &rtd119x_wdt_info;
 	data->wdt_dev.ops = &rtd119x_wdt_ops;
 	data->wdt_dev.timeout = 120;
-	data->wdt_dev.max_timeout = 0xffffffff / clk_get_rate(data->clk);
+	data->wdt_dev.max_timeout = 0xffffffff / rate;
 	data->wdt_dev.min_timeout = 1;
 	data->wdt_dev.parent = dev;