From 785908cf19c9eb4803f6bf9c0a7447dc3661d5c3 Mon Sep 17 00:00:00 2001
From: Jaehyun Chung <jaehyun.chung@amd.com>
Date: Mon, 19 Aug 2019 16:45:05 -0400
Subject: drm/amd/display: OTC underflow fix
Git-commit: 785908cf19c9eb4803f6bf9c0a7447dc3661d5c3
Patch-mainline: v5.5-rc1
References: bsc#1152489
[Why] Underflow occurs on some display setups(repro'd on 3x4K HDR) on boot,
mode set, and hot-plugs with. Underflow occurs because mem clk
is not set high after disabling pstate switching. This behaviour occurs
because some calculations assumed displays were synchronized.
[How] Add a condition to check if timing sync is disabled so that
synchronized vblank can be set to false.
Signed-off-by: Jaehyun Chung <jaehyun.chung@amd.com>
Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
index 5a9d3c85eaaa..630f6a7be0ce 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -1759,7 +1759,7 @@ int dcn20_populate_dml_pipes_from_context(
pipe_cnt = i;
continue;
}
- if (!resource_are_streams_timing_synchronizable(
+ if (dc->debug.disable_timing_sync || !resource_are_streams_timing_synchronizable(
res_ctx->pipe_ctx[pipe_cnt].stream,
res_ctx->pipe_ctx[i].stream)) {
synchronized_vblank = false;
--
2.28.0