drm/i915: Fix ADL+ tiled plane stride when the POT stride is smaller than the original
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Mon, 4 Dec 2023 20:24:43 +0000 (22:24 +0200)
committerVille Syrjälä <ville.syrjala@linux.intel.com>
Tue, 5 Dec 2023 17:55:19 +0000 (19:55 +0200)
commit01a39f1c4f1220a4e6a25729fae87ff5794cbc52
tree9ba1527ec8ee45c211bbbe8a93a341de660f5983
parent4de77156a2acdec0014fa89fc1766a7410d726ff
drm/i915: Fix ADL+ tiled plane stride when the POT stride is smaller than the original

plane_view_scanout_stride() currently assumes that we had to pad the
mapping stride with dummy pages in order to align it. But that is not
the case if the original fb stride exceeds the aligned stride used
to populate the remapped view, which is calculated from the user
specified framebuffer width rather than the user specified framebuffer
stride.

Ignore the original fb stride in this case and just stick to the POT
aligned stride. Getting this wrong will cause the plane to fetch the
wrong data, and can lead to fault errors if the page tables at the
bogus location aren't even populated.

TODO: figure out if this is OK for CCS, or if we should instead increase
the width of the view to cover the entire user specified fb stride
instead...

Cc: Imre Deak <imre.deak@intel.com>
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204202443.31247-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
drivers/gpu/drm/i915/display/intel_fb.c