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From: Chaitanya Sabnis <chaitanya.msabnis@gmail.com>
To: brgl@kernel.org, andi.shyti@kernel.org
Cc: linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Chaitanya Sabnis <chaitanya.msabnis@gmail.com>,
	Sashiko <sashiko-bot@kernel.org>
Subject: [PATCH v3] i2c: davinci: fix division by zero on missing clock-frequency
Date: Fri, 15 May 2026 14:55:20 +0530	[thread overview]
Message-ID: <20260515092520.9006-1-chaitanya.msabnis@gmail.com> (raw)

When the 'clock-frequency' property is missing from the device tree,
the driver falls back to DAVINCI_I2C_DEFAULT_BUS_FREQ. However, this
macro was defined in kHz (100), whereas the device tree property is
expected in Hz.

The probe function divided the fallback value by 1000, causing
integer truncation that resulted in dev->bus_freq = 0. This triggered
a deterministic division-by-zero kernel panic when calculating clock
dividers later in the probe sequence.

Fix this by redefining DAVINCI_I2C_DEFAULT_BUS_FREQ in Hz (100000)
to match the expected device tree property unit, allowing the existing
division logic to work correctly for both cases.

Fixes: b04ce6385979 ("i2c: davinci: kill platform data")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260514044726.57297C2BCB7@smtp.kernel.org/
Signed-off-by: Chaitanya Sabnis <chaitanya.msabnis@gmail.com>
---
 drivers/i2c/busses/i2c-davinci.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index a773ba082321..a264a480dc3c 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -117,7 +117,7 @@
 /* timeout for pm runtime autosuspend */
 #define DAVINCI_I2C_PM_TIMEOUT	1000	/* ms */
 
-#define DAVINCI_I2C_DEFAULT_BUS_FREQ	100
+#define DAVINCI_I2C_DEFAULT_BUS_FREQ	100000
 
 struct davinci_i2c_dev {
 	struct device           *dev;
@@ -761,9 +761,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 	r = device_property_read_u32(&pdev->dev, "clock-frequency", &prop);
 	if (r)
 		prop = DAVINCI_I2C_DEFAULT_BUS_FREQ;
-
 	dev->bus_freq = prop / 1000;
-
 	dev->has_pfunc = device_property_present(&pdev->dev, "ti,has-pfunc");
 
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
-- 
2.43.0



                 reply	other threads:[~2026-05-15  9:26 UTC|newest]

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