[PATCH v5 06/13] drm/mediatek: Turn off the layers with zero width or height

[Shawn Sung (宋孝謙)]

Hi CK,

On Fri, 2024-03-01 at 07:51 +0000, CK Hu (胡俊光) wrote:
> Hi, Hsiao-chien:
> 
> On Thu, 2024-02-15 at 18:11 +0800, Hsiao Chien Sung wrote:
> > We found that IGT (Intel GPU Tool) will try to commit layers with
> > zero width or height and lead to undefined behaviors in hardware.
> > Disable the layers in such a situation.
> 
> Reviewed-by: CK Hu <ck.hu at mediatek.com>
> 
> I have reviewed ovl driver, ovl does not have this limitation, so
> it's
> better to point out which hardware has this limitation. That's OK if
> you have no information.
> 
Thank you for the confirmation. After checking with the designer, for
MT8195/MT8188, the height setting in OVL can be 0 but width cannot,
otherwise the hardware could hang. Although we are not sure if other
old platforms have the same behavior.

Regards,
Shawn