Re: [Intel-gfx] [PATCH 3/5] drm/i915: Remove redundant framebuffer format check

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Jan 12, 2023 at 11:07:59AM -0300, Maíra Canal wrote:
> Hi,
> 
> On 1/12/23 09:43, Ville Syrjälä wrote:
> > On Mon, Jan 09, 2023 at 07:58:06AM -0300, Maíra Canal wrote:
> >> Now that framebuffer_check() verifies that the format is properly
> >> supported, there is no need to check it again on i915's inside
> >> helpers.
> >>
> >> Therefore, remove the redundant framebuffer format check from the
> >> intel_framebuffer_init() function, letting framebuffer_check()
> >> perform the framebuffer validation.
> >>
> >> Signed-off-by: Maíra Canal <mcanal@igalia.com>
> >> ---
> >>   drivers/gpu/drm/i915/display/intel_fb.c | 9 ---------
> >>   1 file changed, 9 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
> >> index 63137ae5ab21..230b729e42d6 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_fb.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> >> @@ -1914,15 +1914,6 @@ int intel_framebuffer_init(struct intel_framebuffer *intel_fb,
> >>   		}
> >>   	}
> >>   
> >> -	if (!drm_any_plane_has_format(&dev_priv->drm,
> >> -				      mode_cmd->pixel_format,
> >> -				      mode_cmd->modifier[0])) {
> >> -		drm_dbg_kms(&dev_priv->drm,
> >> -			    "unsupported pixel format %p4cc / modifier 0x%llx\n",
> >> -			    &mode_cmd->pixel_format, mode_cmd->modifier[0]);
> >> -		goto err;
> >> -	}
> >> -
> > 
> > This doesn't work for the legacy tiling->modifier path.
> 
> Do you have any idea on how we could remove drm_any_plane_has_format() from
> i915? Or is it strictly necessary to validate the modifier in the legacy
> path?

I guess techinically we could skip it by knowing that X-tile is always
supported. However that may not hold in the future so not a soution I
really like. Also the drm_any_plane_has_format() call from 
framebuffer_check() is too early, so instead of checking X-tile
vs. linear based on the tiling it's going to always assume linear.

-- 
Ville Syrjälä
Intel