From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> commit 6eb3cf2e06d22b2b08e6b0ab48cb9c05a8e1a107 upstream. [Why] Changes that are fast don't require updating DLG parameters making this call unnecessary. Considering this is an expensive call it should not be done on every flip. DML touches clocks, p-state support, DLG params and a few other DC internal flags and these aren't expected during fast. A hang has been reported with this change when called on every flip which suggests that modifying these fields is not recommended behavior on fast updates. [How] Guard the validation to only happen if update type isn't FAST. Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1191 Fixes: a24eaa5c51255b ("drm/amd/display: Revalidate bandwidth before commiting DC updates") Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> Acked-by: Alex Deucher <alexander.deucher@xxxxxxx> Reviewed-by: Roman Li <Roman.Li@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/dc/core/dc.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -2226,10 +2226,12 @@ void dc_commit_updates_for_stream(struct copy_stream_update_to_stream(dc, context, stream, stream_update); - if (!dc->res_pool->funcs->validate_bandwidth(dc, context, false)) { - DC_ERROR("Mode validation failed for stream update!\n"); - dc_release_state(context); - return; + if (update_type > UPDATE_TYPE_FAST) { + if (!dc->res_pool->funcs->validate_bandwidth(dc, context, false)) { + DC_ERROR("Mode validation failed for stream update!\n"); + dc_release_state(context); + return; + } } commit_planes_for_stream(
