[Intel-gfx] [PATCH] drm/i915: Fix SKL+ 90/270 degree rotated plane coordinate computation

[Chris Wilson]

On Mon, Oct 24, 2016 at 07:13:04PM +0300, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Pass the framebuffer size in .16 fixed point coordinates to
> drm_rect_rotate() since that's what the source coordinates are as well
> at this stage. We used to do this part of the computation in integer
> coordinates, but that got changed when moving the computation to
> happen in the check phase of the operation. Unfortunately I forgot
> to shift up the fb width and height appropriately.
> 
> With the bogus size we ended up with some negative fb offset, which when
> added to the vma offset caused out scanout to start at an offset earlier
> than we inteded. Eg. when testing on my SKL I saw a row of incorrect
> tiles at the top of my screen.
> 
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
> Cc: drm-intel-fixes at lists.freedesktop.org
> Fixes: b63a16f6cd89 ("drm/i915: Compute display surface offset in the plane check hook for SKL+")
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 5a036999487b..c783f884f85d 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -2985,7 +2985,8 @@ int skl_check_plane_surface(struct intel_plane_state *plane_state)
>  	/* Rotate src coordinates to match rotated GTT view */
>  	if (drm_rotation_90_or_270(rotation))
>  		drm_rect_rotate(&plane_state->base.src,
> -				fb->width, fb->height, DRM_ROTATE_270);
> +				fb->width << 16, fb->height << 16,
> +				DRM_ROTATE_270);

Line 2576 (intel_fill_fb_info()) also looks wrong.

drm_rect_rotate(&r,
		rot_info->plane[i].width * tile_width,
		rot_info->plane[i].height * tile_height,
		DRM_ROTATE_270);
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre