[PATCH] i2c: designware: don't infer timings described by ACPI from clock rate

[Jarkko Nikula]

On 05/19/2017 11:56 AM, Ard Biesheuvel wrote:
> Commit bd698d24b1b57 ("i2c: designware: Get selected speed mode
> sda-hold-time via ACPI") updated the logic that reads the timing
> parameters for various I2C bus rates from the DSDT, to only read
> the timing parameters for the currently selected mode.
>
> This causes a WARN_ON() splat on platforms that legally omit the clock
> frequency from the ACPI description, because in the new situation, the
> core I2C designware driver still accesses the fields in the driver
> struct that we no longer populate, and proceeds to calculate them from
> the clock frequency. Since the clock frequency is unspecified, the
> driver complains loudly using a WARN_ON().
>
> So revert back to the old situation, where the struct fields for all
> timings are populated, but retain the new logic which chooses the SDA
> hold time from the timing mode that is currently in use.
>
> Fixes: bd698d24b1b57 ("i2c: designware: Get selected speed mode ...")
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---
>  drivers/i2c/busses/i2c-designware-platdrv.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)
>
Thanks, this is ok to me. Let's add also kudos to Lorenzo:

Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
Acked-by: Jarkko Nikula <jarkko.nikula at linux.intel.com>