[PATCH 0/5] drm/fb-helper: Fix and improve fbdevio clipping

[Thomas Zimmermann]

This is one of several patchset s to improve fb deferred I/O and
DRM's use of it. THe patches fix several problems with the current
helpers and add some easy improvements.

Deferred I/O tracks dirty pages of the screen buffer, from which
DRM calculates a bounding box of the damaged area. Patches 1 and 2
resolve bugs in the computation. Speifically, it makes the damage
handling work with overallocation and panning enabled.

Patches 3 to 5 add an easy performance improvement. Instead of
damaging the whole viewport after a write operation, only damage
the written area. For large writes the area consists of multiple
scanlines, for small writes the area might consist of only a few
pixels on a single scanline. Write operations now also work correctly
with overallocation and panning enabled.

Thomas Zimmermann (5):
  drm/fb-helper: Fix clip rectangle height
  drm/fb-helper: Fix vertical damage clipping
  drm/fb-helper: Calculate damaged area in separate helper
  drm/fb-helper: Clip damage area to written memory range
  drm/fb-helper: Clip damage area horizontally

 drivers/gpu/drm/drm_fb_helper.c | 69 ++++++++++++++++++++++++++-------
 1 file changed, 54 insertions(+), 15 deletions(-)


base-commit: 0bb81b5d6db5f689b67f9d8b35323235c45e890f
prerequisite-patch-id: c2b2f08f0eccc9f5df0c0da49fa1d36267deb11d
prerequisite-patch-id: c67e5d886a47b7d0266d81100837557fda34cb24
prerequisite-patch-id: 8e52143a6cd7b8fb789e656208f6edde71d0f499
prerequisite-patch-id: 4b0e798cb2990b553d44e1bc39634d72d172ea7b
-- 
2.34.1