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| author | Lyude Paul <lyude@redhat.com> | 2022-08-17 15:38:37 -0400 |
|---|---|---|
| committer | Lyude Paul <lyude@redhat.com> | 2022-08-23 16:53:37 -0400 |
| commit | a5c2c0d164e96d24f73faffcd3b7bbb607e701a9 (patch) | |
| tree | e534e930f8acf5942de00c54e3043cae6a2a34b6 /drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | |
| parent | 0b4e477e08a14ef852d5a633cee10e4187730005 (diff) | |
| download | lwn-a5c2c0d164e96d24f73faffcd3b7bbb607e701a9.tar.gz lwn-a5c2c0d164e96d24f73faffcd3b7bbb607e701a9.zip | |
drm/display/dp_mst: Add nonblocking helpers for DP MST
As Daniel Vetter pointed out, if we only use the atomic modesetting locks
with MST it's technically possible for a driver with non-blocking modesets
to race when it comes to MST displays - as we make the mistake of not doing
our own CRTC commit tracking in the topology_state object.
This could potentially cause problems if something like this happens:
* User starts non-blocking commit to disable CRTC-1 on MST topology 1
* User starts non-blocking commit to enable CRTC-2 on MST topology 1
There's no guarantee here that the commit for disabling CRTC-2 will only
occur after CRTC-1 has finished, since neither commit shares a CRTC - only
the private modesetting object for MST. Keep in mind this likely isn't a
problem for blocking modesets, only non-blocking.
So, begin fixing this by keeping track of which CRTCs on a topology have
changed by keeping track of which CRTCs we release or allocate timeslots
on. As well, add some helpers for:
* Setting up the drm_crtc_commit structs in the ->commit_setup hook
* Waiting for any CRTC dependencies from the previous topology state
v2:
* Use drm_dp_mst_atomic_setup_commit() directly - Jani
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-9-lyude@redhat.com
Diffstat (limited to 'drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index cd30b02af8ee..c97a4d759b94 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2808,7 +2808,8 @@ static const struct drm_mode_config_funcs amdgpu_dm_mode_funcs = { }; static struct drm_mode_config_helper_funcs amdgpu_dm_mode_config_helperfuncs = { - .atomic_commit_tail = amdgpu_dm_atomic_commit_tail + .atomic_commit_tail = amdgpu_dm_atomic_commit_tail, + .atomic_commit_setup = drm_dp_mst_atomic_setup_commit, }; static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) @@ -7959,6 +7960,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) DRM_ERROR("Waiting for fences timed out!"); drm_atomic_helper_update_legacy_modeset_state(dev, state); + drm_dp_mst_atomic_wait_for_dependencies(state); dm_state = dm_atomic_get_new_state(state); if (dm_state && dm_state->context) { @@ -8357,7 +8359,6 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) dc_release_state(dc_state_temp); } - static int dm_force_atomic_commit(struct drm_connector *connector) { int ret = 0; |