Reviewed-by: Alex Hung <[email protected]> On 10/26/26 01:33, Mikhail Gavrilov wrote:
After resume from S3, DC enables SubVP on a single FreeSync display at a high refresh rate, although dcn32_allow_subvp_high_refresh_rate() is meant to keep SubVP off that configuration ("For single display cases, freesync must be disabled"). On an RX 7900 XTX driving a FreeSync TV at 3840x2160@120, amdgpu_dm_capabilities reports sub-viewport disabled after boot and enabled after "rtcwake -m mem", and the memory clock starts switching. It stays that way until a later commit re-validates the state; a CRTC gamma change (toggling Night Light) turns SubVP off again.The policy reads dc_stream_state::allow_freesync while the new state is validated, but amdgpu_dm sets that field only in amdgpu_dm_update_freesync_state_on_stream(), on the first flip after the commit. A stream created by a modeset is therefore validated as if FreeSync were off. On resume, dm_destroy_cached_state() drops the streams and forces a modeset, so the resumed state is validated without FreeSync. Set allow_freesync in amdgpu_dm_get_freesync_config_for_crtc(), which atomic check calls for every active CRTC and which already writes ignore_msa_timing_param to the stream. It uses vrr_supported, the condition the flip-time value is derived from. With this change the same TV keeps SubVP disabled across "rtcwake -m mem". On this machine SubVP is also what exposes the single-frame scanout corruption reported in the thread linked below, so the FreeSync setting stopped working as a workaround after every suspend. Fixes: 87f0c16e0eeb ("drm/amd/display: Enable SubVP for high refresh rate displays") Link: https://lore.kernel.org/all/[email protected]/ Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5714#note_3736349 Tested-by: Josh Kasten <[email protected]> Signed-off-by: Mikhail Gavrilov <[email protected]> --- v2: - Rebased onto amd-staging-drm-next, where vrr_supported also depends on vrr_timing_valid, so v1 no longer applied there. No functional change. - Added Tested-by from Josh Kasten, who ran v2 on next-20261023 (the file is the same there as in amd-staging-drm-next) and saw SubVP stay disabled across rtcwake with FreeSync enabled.v1: https://lore.kernel.org/all/[email protected]/.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_freesync.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_freesync.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_freesync.c index 386ba88c57c6..936a899aef00 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_freesync.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_freesync.c @@ -170,6 +170,14 @@ void amdgpu_dm_get_freesync_config_for_crtc( vrefresh <= aconnector->max_vfreq && vrr_timing_valid;+ /*+ * DC reads allow_freesync while validating the new state, for example + * to keep SubVP off a single FreeSync display, but it is otherwise set + * only on the first flip after the commit. Set it here, so that a + * stream created by this commit is not validated without it. + */ + new_crtc_state->stream->allow_freesync = new_crtc_state->vrr_supported; + if (new_crtc_state->vrr_supported) { new_crtc_state->stream->ignore_msa_timing_param = true; fs_vid_mode = new_crtc_state->freesync_config.state == VRR_STATE_ACTIVE_FIXED;
