On Tue, Oct 29, 2024 at 05:54:10PM +0800, Chen-Yu Tsai wrote:
> The IT6505 bridge chip has a active low reset line. Since it is a
> "reset" and not an "enable" line, the GPIO should be asserted to
> put it in reset and deasserted to bring it out of reset during
> the power on sequence.
>
> The polarity was inverted when the driver was first introduced, likely
> because the device family that was targeted had an inverting level
> shifter on the reset line.
>
> The MT8186 Corsola devices already have the IT6505 in their device tree,
> but the whole display pipeline is actually disabled and won't be enabled
> until some remaining issues are sorted out. The other known user is
> the MT8183 Kukui / Jacuzzi family; their device trees currently do not
> have the IT6505 included.
>
> Fix the polarity in the driver while there are no actual users.
>
> Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/ite-it6505.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
The datasheet describes the pin as Active LOW, so the change seems to be
correct.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
--
With best wishes
Dmitry
