drm/amd/display: re-enable wait in pipelock, but add timeout

Removing this causes hangs in some games, so re-add it, but add
a timeout so we don't hang while switching flip types.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=205169
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=112266
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
index 03e4aaf..d5c18fb 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1112,6 +1112,25 @@ void dcn20_pipe_control_lock(
        if (pipe->plane_state != NULL)
                flip_immediate = pipe->plane_state->flip_immediate;
 
+       if (flip_immediate && lock) {
+               const int TIMEOUT_FOR_FLIP_PENDING = 100000;
+               int i;
+
+               for (i = 0; i < TIMEOUT_FOR_FLIP_PENDING; ++i) {
+                       if (!pipe->plane_res.hubp->funcs->hubp_is_flip_pending(pipe->plane_res.hubp))
+                               break;
+                       udelay(1);
+               }
+
+               if (pipe->bottom_pipe != NULL) {
+                       for (i = 0; i < TIMEOUT_FOR_FLIP_PENDING; ++i) {
+                               if (!pipe->bottom_pipe->plane_res.hubp->funcs->hubp_is_flip_pending(pipe->bottom_pipe->plane_res.hubp))
+                                       break;
+                               udelay(1);
+                       }
+               }
+       }
+
        /* In flip immediate and pipe splitting case, we need to use GSL
         * for synchronization. Only do setup on locking and on flip type change.
         */