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

[Chaitanya Sabnis]

Hi Andrew,

That makes complete sense. Updating the macro to Hz is a much cleaner
approach and aligns perfectly with the expected unit of the device
tree property.

I have track down the original commit for the Fixes: tag and send out a v2.

Thanks for the review!
Chaitanya


On Thu, May 14, 2026 at 5:46 PM Andrew Lunn <andrew at lunn.ch> wrote:
>
> On Thu, May 14, 2026 at 04:07:40PM +0530, Chaitanya Sabnis wrote:
> > When the 'clock-frequency' property is missing from the device tree,
> > the driver falls back to DAVINCI_I2C_DEFAULT_BUS_FREQ. However, this
> > macro is defined in kHz (100), whereas the device tree property is
> > expected in Hz.
> >
> > The probe function blindly 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 isolating the division so it only applies to the Hz value
> > read from the device tree, cleanly assigning the kHz default otherwise.
>
> Why not keep the patch simple and just change the value of
> DAVINCI_I2C_DEFAULT_BUS_FREQ to Hz?
>
> > Reported-by: Sashiko <sashiko-bot at kernel.org>
> > Closes: https://lore.kernel.org/all/20260514044726.57297C2BCB7@smtp.kernel.org/
> > Signed-off-by: Chaitanya Sabnis <chaitanya.msabnis at gmail.com>
>
> Please also added a Fixes: tag.
>
>        Andrew