drm/i915: Add display WA #1175 for planes ending close to right screen edge

As described in the WA on GLK and CNL planes on the right edge of the
screen that have less than 4 pixels visible from the beginning of the
plane to the edge of the screen can cause FIFO underflow and display
corruption.

On GLK/CNL I could trigger the problem only if the plane was at the same
time also aligned to the top edge of the screen (after clipping) and
there were exactly 2 pixels visible from the start of the plane to the
right edge of the screen (so couldn't trigger it with 1 or 3 pixels
visible). Nevertheless, to be sure, I also applied the WA for these cases.

I also couldn't see any problem with the cursor plane and later Art
confirmed that it's not affected, so the WA is applied only for the
other plane types.

v2:
- Use -ERANGE instead of -EINVAL. (Chris)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180116112415.22060-1-imre.deak@intel.com

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index bb849b55548c..1695b2a76c13 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1507,7 +1507,8 @@ u32 skl_plane_ctl(const struct intel_crtc_state *crtc_state,
 		  const struct intel_plane_state *plane_state);
 u32 skl_plane_stride(const struct drm_framebuffer *fb, int plane,
 		     unsigned int rotation);
-int skl_check_plane_surface(struct intel_plane_state *plane_state);
+int skl_check_plane_surface(const struct intel_crtc_state *crtc_state,
+			    struct intel_plane_state *plane_state);
 int i9xx_check_plane_surface(struct intel_plane_state *plane_state);
 
 /* intel_csr.c */