[PATCH 39/43] drm/amd/display: Use udelay to avoid context switch

[Rodrigo Siqueira]

From: Martin Tsai <martin.tsai at amd.com>

[why]
The rapid msleep operation causes the white line garbage when
DAL check flip pending status in SetVidPnSourceVisibility.
To execute this msleep will induce context switch, and longer
delay could cause worse garbage situation.

[how]
To replace msleep with udelay.

Signed-off-by: Martin Tsai <martin.tsai at amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng at amd.com>
Acked-by: Harry Wentland <harry.wentland at amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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 89920924a154..0dc652e76848 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1642,9 +1642,9 @@ void dcn20_program_front_end_for_ctx(
 			struct hubp *hubp = pipe->plane_res.hubp;
 			int j = 0;
 
-			for (j = 0; j < TIMEOUT_FOR_PIPE_ENABLE_MS
+			for (j = 0; j < TIMEOUT_FOR_PIPE_ENABLE_MS*1000
 					&& hubp->funcs->hubp_is_flip_pending(hubp); j++)
-				msleep(1);
+				udelay(1);
 		}
 	}
 
-- 
2.24.1