On 12/17/24 1:45 PM, Melissa Wen wrote:
Hi,
Some issues have been found by Cosmic users of AMD display since the
introduction of cursor overlay mode: page fault and divide errors
causing interface freezes. Both are 100% reproducible and affects
multiple HW versions.
Patch 1 addresses the page fault error by resolving the definition
mismatch around the number of surfaces supported by the hw, where two
different values (MAX_SURFACES and MAX_SURFACE_NUM) would be taken
through the DC surface updates flow. The regular flow take MAX_SURFACES
== 3 into account and commit_minimal_transition_state uses
MAX_SURFACE_NUM == 6. I noticed that Leo Li has proposed this change in
a previous discussion [1], so I added a Suggested-by tag.
Patch 2 expands the maximum number of surfaces to four, since it's
supported by the hw. Also, this amount accomodates current needs,
avoiding `dc_state_add_plane` complaints of not enough resource. Note
that it somehow reverts the change proposed by [2].
Related AMD issues:
- https://gitlab.freedesktop.org/drm/amd/-/issues/3693
- https://gitlab.freedesktop.org/drm/amd/-/issues/3594
Patch 3 fixes a kernel oops due to division by zero error by checking if
the destination scale size is zero, avoiding calculation and just
setting the out-scale size to zero, similar to what is done by
drm_calc_scale(). Even though the missing check in dm_get_plane_scale()
wasn't introduced by cursor overlay mode, AFAIU the cursor mode
assessment happens before plane state checks, so
amdgpu_dm_plane_helper_check_state() can't prevent
dm_crtc_get_cursor_mode() taking an invisible plane into account.
Related AMD issue:
- https://gitlab.freedesktop.org/drm/amd/-/issues/3729
Other previous discussions can be found at:
- https://lore.kernel.org/amd-gfx/20241114143741.627128-1-zaeem.mohamed@xxxxxxx/
- https://lore.kernel.org/amd-gfx/20240925154324.348774-1-mwen@xxxxxxxxxx/
Thanks in advance for any feedback.
Melissa
[1] https://lore.kernel.org/amd-gfx/20241025193727.765195-2-zaeem.mohamed@xxxxxxx/
[2] https://gitlab.freedesktop.org/agd5f/linux/-/commit/3cfd03b79425c
Melissa Wen (3):
drm/amd/display: fix page fault due to max surface definition mismatch
drm/amd/display: increase MAX_SURFACES to the value supported by hw
drm/amd/display: fix divide error in DM plane scale calcs
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++--
drivers/gpu/drm/amd/display/dc/core/dc.c | 2 +-
drivers/gpu/drm/amd/display/dc/core/dc_state.c | 8 ++++----
drivers/gpu/drm/amd/display/dc/dc.h | 4 ++--
drivers/gpu/drm/amd/display/dc/dc_stream.h | 2 +-
drivers/gpu/drm/amd/display/dc/dc_types.h | 1 -
drivers/gpu/drm/amd/display/dc/dml2/dml2_mall_phantom.c | 2 +-
7 files changed, 11 insertions(+), 12 deletions(-)
Hi Melissa,
Thanks a lot for your series. I tested it on a couple of hardware
devices, and I think everything is alright.
Series is
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
and your series was merged into the amd-staging-drm-next.
Thanks
Siqueira
