From 9d58fc503052dd7ac3ea333ac098046a8d77cd2a Mon Sep 17 00:00:00 2001 From: Saaem Rizvi Date: Mon, 27 Feb 2023 18:55:07 -0500 Subject: [PATCH] drm/amd/display: Remove OTG DIV register write for Virtual signals. [ Upstream commit 709671ffb15dcd1b4f6afe2a9d8c67c7c4ead4a1 ] [WHY] Hot plugging and then hot unplugging leads to k1 and k2 values to change, as signal is detected as a virtual signal on hot unplug. Writing these values to OTG_PIXEL_RATE_DIV register might cause primary display to blank (known hw bug). [HOW] No longer write k1 and k2 values to register if signal is virtual, we have safe guards in place in the case that k1 and k2 is unassigned so that an unknown value is not written to the register either. Cc: stable@vger.kernel.org Cc: Mario Limonciello Reviewed-by: Samson Tam Reviewed-by: Alvin Lee Acked-by: Qingqing Zhuo Signed-off-by: Saaem Rizvi Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c index e119f4f76fdc..30d15a94f720 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c @@ -1184,7 +1184,7 @@ unsigned int dcn32_calculate_dccg_k1_k2_values(struct pipe_ctx *pipe_ctx, unsign *k2_div = PIXEL_RATE_DIV_BY_2; else *k2_div = PIXEL_RATE_DIV_BY_4; - } else if (dc_is_dp_signal(stream->signal) || dc_is_virtual_signal(stream->signal)) { + } else if (dc_is_dp_signal(stream->signal)) { if (two_pix_per_container) { *k1_div = PIXEL_RATE_DIV_BY_1; *k2_div = PIXEL_RATE_DIV_BY_2;