[PATCH v2] i2c: davinci: fix division by zero on missing clock-frequency

Chaitanya Sabnis posted 1 patch 4 weeks ago
There is a newer version of this series
drivers/i2c/busses/i2c-davinci.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
[PATCH v2] i2c: davinci: fix division by zero on missing clock-frequency
Posted by Chaitanya Sabnis 4 weeks ago
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 | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index a773ba082321..bd0754abdcb7 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -760,9 +760,9 @@ 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->bus_freq = DAVINCI_I2C_DEFAULT_BUS_FREQ;
+	else
+		dev->bus_freq = prop / 1000;
 
 	dev->has_pfunc = device_property_present(&pdev->dev, "ti,has-pfunc");
 
-- 
2.43.0