[PATCH] drm: Check actual format for legacy pageflip.

[Liu, Zhan]

[AMD Official Use Only - Internal Distribution Only]

> -----Original Message-----
> From: Liu, Zhan <Zhan.Liu at amd.com>
> Sent: 2021/January/04, Monday 3:46 PM
> To: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>; Mario Kleiner
> <mario.kleiner.de at gmail.com>
> Cc: dri-devel <dri-devel at lists.freedesktop.org>; amd-gfx list <amd-
> gfx at lists.freedesktop.org>; Deucher, Alexander
> <Alexander.Deucher at amd.com>; Daniel Vetter <daniel.vetter at ffwll.ch>;
> Kazlauskas, Nicholas <Nicholas.Kazlauskas at amd.com>; Ville Syrjälä
> <ville.syrjala at linux.intel.com>
> Subject: Re: [PATCH] drm: Check actual format for legacy pageflip.
>
>
>
> + Ville
>
> On Sat, Jan 2, 2021 at 4:31 PM Mario Kleiner <mario.kleiner.de at gmail.com>
> wrote:
> >
> > On Sat, Jan 2, 2021 at 3:02 PM Bas Nieuwenhuizen
> > <bas at basnieuwenhuizen.nl> wrote:
> > >
> > > With modifiers one can actually have different format_info structs
> > > for the same format, which now matters for AMDGPU since we convert
> > > implicit modifiers to explicit modifiers with multiple planes.
> > >
> > > I checked other drivers and it doesn't look like they end up
> > > triggering this case so I think this is safe to relax.
> > >
> > > Signed-off-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
> > > Fixes: 816853f9dc40 ("drm/amd/display: Set new format info for
> > >converted metadata.")
> > > ---
> > >  drivers/gpu/drm/drm_plane.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_plane.c
> > > b/drivers/gpu/drm/drm_plane.c index e6231947f987..f5085990cfac
> > > 100644
> > > --- a/drivers/gpu/drm/drm_plane.c
> > > +++ b/drivers/gpu/drm/drm_plane.c
> > > @@ -1163,7 +1163,7 @@ int drm_mode_page_flip_ioctl(struct
> drm_device
> > >*dev,
> > >         if (ret)
> > >                 goto out;
> > >
> > > -       if (old_fb->format != fb->format) {
> > > +       if (old_fb->format->format != fb->format->format) {
> >
>
> I agree with this patch, though considering the original way was made by
> Ville, I will wait for Ville's input first. Adding my "Acked-by" here.
>
> This patch is:
> Acked-by: Zhan Liu <zhan.liu at amd.com>

Ping...

>
> > This was btw. the original way before Ville made it more strict about
> > 4 years ago, to catch issues related to tiling, and more complex
> > layouts, like the dcc tiling/retiling introduced by your modifier
> > patches. That's why I hope my alternative patch is a good solution for
> > atomic drivers while keeping the strictness for potential legacy
> > drivers.
> >
> > -mario
> >
> > >                 DRM_DEBUG_KMS("Page flip is not allowed to change
> > >frame buffer format.\n");
> > >                 ret = -EINVAL;
> > >                 goto out;
> > > --
> > > 2.29.2
> > >