[PATCH AUTOSEL 5.10 20/20] drm/amd/display: workaround for hard hang on HPD on native DP
From: Sasha Levin <sashal@kernel.org>
Date: 2021-08-10 14:18:30
Also in:
amd-gfx, dri-devel, lkml
Subsystem:
amd display core, drm drivers, radeon and amdgpu drm drivers, the rest · Maintainers:
Harry Wentland, Leo Li, David Airlie, Simona Vetter, Alex Deucher, Christian König, Linus Torvalds
From: Qingqing Zhuo <redacted> [ Upstream commit c4152b297d56d3696ad0a9003169bc5b98ad7b72 ] [Why] HPD disable and enable sequences are not mutually exclusive on Linux. For HPDs that spans over 1s (i.e. HPD low = 1s), part of the disable sequence (specifically, a request to SMU to lower refclk) could come right before the call to PHY enable, causing DMUB to access an unresponsive PHY and thus a hard hang on the system. [How] Disable 48mhz refclk off on native DP. Reviewed-by: Hersen Wu <redacted> Acked-by: Aurabindo Pillai <redacted> Signed-off-by: Qingqing Zhuo <redacted> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 4 +++- 1 file changed, 3 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 1c6e401dd4cc..0eba391e597f 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@@ -66,9 +66,11 @@ int rn_get_active_display_cnt_wa( for (i = 0; i < context->stream_count; i++) { const struct dc_stream_state *stream = context->streams[i]; + /* Extend the WA to DP for Linux*/ if (stream->signal == SIGNAL_TYPE_HDMI_TYPE_A || stream->signal == SIGNAL_TYPE_DVI_SINGLE_LINK || - stream->signal == SIGNAL_TYPE_DVI_DUAL_LINK) + stream->signal == SIGNAL_TYPE_DVI_DUAL_LINK || + stream->signal == SIGNAL_TYPE_DISPLAY_PORT) tmds_present = true; }
--
2.30.2