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| author | Samson Tam <Samson.Tam@amd.com> | 2019-06-04 15:52:59 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-07-18 14:17:19 -0500 |
| commit | 4fc1609bcd5475a9cef1caeb10a04106f4f85fac (patch) | |
| tree | 65dce2dc9cb324e4903719aa1f061030036d98df /drivers/gpu/drm/amd | |
| parent | 4a876eecf6a5bfbe05ca6358e1b6a484e27ce32f (diff) | |
| download | linux-4fc1609bcd5475a9cef1caeb10a04106f4f85fac.tar.gz linux-4fc1609bcd5475a9cef1caeb10a04106f4f85fac.tar.bz2 linux-4fc1609bcd5475a9cef1caeb10a04106f4f85fac.zip | |
drm/amd/display: skip retrain in dc_link_set_preferred_link_settings() if using passive dongle
[Why]
Fixes issue when we have a display connected using a passive
dongle and then emulate over it using a DP connection at 1 x 1.62 Ghz.
System hangs because register bus returns back 0xFFFFFFFF for all
register reads after setting register DIG_BE_CNTL in
dcn10_link_encoder_connect_dig_be_to_fe(). Hang occurs later
when trying to do a register read.
[How]
At the start of the emulation, dc_link_set_preferred_link_settings()
and dp_retrain_link_dp_test() is called, even though it is connected
using a passive dongle.
Add an extra condition in dp_retrain_link_dp_test() to check for
link->dongle_max_pix_clk > 0. This is the only way we know if the
connection is using passive dongle so we don't retrain DP.
Signed-off-by: Samson Tam <Samson.Tam@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index 8dbf759eba45..435d50356bad 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -2984,8 +2984,10 @@ void dc_link_set_preferred_link_settings(struct dc *dc, /* Retrain with preferred link settings only relevant for * DP signal type + * Check for non-DP signal or if passive dongle present */ - if (!dc_is_dp_signal(link->connector_signal)) + if (!dc_is_dp_signal(link->connector_signal) || + link->dongle_max_pix_clk > 0) return; for (i = 0; i < MAX_PIPES; i++) { |