drm/amd/display: revert wait in pipelock

[why]
Previous workaround to prevent a vsync flip to be converted
to immediate flip is no longer needed, and is risky because
there are cases where it can result in infinite loop.

[how]
Remove wait loop (which is potentially infinite) before locking
pipe

Signed-off-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@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 161805b..d1c56fe 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1103,17 +1103,6 @@ void dcn20_pipe_control_lock(
        if (pipe->plane_state != NULL)
                flip_immediate = pipe->plane_state->flip_immediate;
 
-       if (flip_immediate && lock) {
-               while (pipe->plane_res.hubp->funcs->hubp_is_flip_pending(pipe->plane_res.hubp)) {
-                       udelay(1);
-               }
-
-               if (pipe->bottom_pipe != NULL)
-                       while (pipe->bottom_pipe->plane_res.hubp->funcs->hubp_is_flip_pending(pipe->bottom_pipe->plane_res.hubp))       {
-                               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.
         */