From 5dd02ddede2992884bf75d26f612836cd10bbbbd Mon Sep 17 00:00:00 2001
From: Peikang Zhang <peikang.zhang@amd.com>
Date: Mon, 8 Jun 2020 14:28:35 -0400
Subject: drm/amd/display: Red screen observed on startup
Git-commit: 3c08d625d6c456fa34dd32e2ae14911ccdfa8c85
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
[Why]
We try to to change new_clocks->dppclk_khz to 100000 when
new_clocks->dppclk_khz is 0
[How]
Don't change new_clocks->dppclk_khz value when new_clocks->dppclk_khz is
0
Signed-off-by: Peikang Zhang <peikang.zhang@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
index 24c5765890fa..39788a7bd003 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c
@@ -153,8 +153,9 @@ void rn_update_clocks(struct clk_mgr *clk_mgr_base,
}
// workaround: Limit dppclk to 100Mhz to avoid lower eDP panel switch to plus 4K monitor underflow.
+ // Do not adjust dppclk if dppclk is 0 to avoid unexpected result
if (!IS_DIAG_DC(dc->ctx->dce_environment)) {
- if (new_clocks->dppclk_khz < 100000)
+ if (new_clocks->dppclk_khz < 100000 && new_clocks->dppclk_khz > 0)
new_clocks->dppclk_khz = 100000;
}
--
2.29.2