diff options
| author | Zhongwei <Zhongwei.Zhang@amd.com> | 2026-01-13 10:51:42 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 15:20:04 +0300 |
| commit | 25c5065bb6766e71fe2cf28bd089b6f62ea8210b (patch) | |
| tree | 952fc15375a61e9197fd384901d5d054879e92b0 | |
| parent | 2d02b419ef8d14603ad4312763897e8d4fd51fab (diff) | |
| download | linux-25c5065bb6766e71fe2cf28bd089b6f62ea8210b.tar.xz | |
drm/amd/display: avoid dig reg access timeout on usb4 link training fail
[ Upstream commit 15b1d7b77e9836ff4184093163174a1ef28bbdd7 ]
[Why]
When usb4 link training fails, the dpia sym clock will be disabled and SYMCLK
source should be changed back to phy clock. In enable_streams, it is
assumed that link training succeeded and will switch from refclk to
phy clock. But phy clk here might not be on. Dig reg access timeout
will occur.
[How]
When enable_stream is hit, check if link training failed for usb4.
If it did, fall back to the ref clock to avoid reg access timeout.
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Zhongwei <Zhongwei.Zhang@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c index 56c1ab6c7330..a4025a09a38a 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c @@ -3055,9 +3055,17 @@ void dcn20_enable_stream(struct pipe_ctx *pipe_ctx) dccg->funcs->enable_symclk32_se(dccg, dp_hpo_inst, phyd32clk); } } else { - if (dccg->funcs->enable_symclk_se) - dccg->funcs->enable_symclk_se(dccg, stream_enc->stream_enc_inst, + if (dccg->funcs->enable_symclk_se && link_enc) { + if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA + && link->cur_link_settings.link_rate == LINK_RATE_UNKNOWN + && !link->link_status.link_active) { + if (dccg->funcs->disable_symclk_se) + dccg->funcs->disable_symclk_se(dccg, stream_enc->stream_enc_inst, link_enc->transmitter - TRANSMITTER_UNIPHY_A); + } else + dccg->funcs->enable_symclk_se(dccg, stream_enc->stream_enc_inst, + link_enc->transmitter - TRANSMITTER_UNIPHY_A); + } } if (dc->res_pool->dccg->funcs->set_pixel_rate_div) |