diff options
| author | George Shen <George.Shen@amd.com> | 2021-11-18 19:25:26 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2021-12-01 16:06:32 -0500 |
| commit | 2f2a4b1879bf6448865af9bdab61d1b7986f6dd0 (patch) | |
| tree | 9f8093617df257ee39b8433798667de5ef37e77a /drivers/gpu/drm | |
| parent | c11099b0d1aa3e48e9578b440886d8b29779e8ba (diff) | |
| download | linux-2f2a4b1879bf6448865af9bdab61d1b7986f6dd0.tar.bz2 | |
drm/amd/display: Skip vendor specific LTTPR w/a outside link training
[Why]
Vendor specific link rate toggle workaround should not be
applied outside of link training scenario, such as when
outputting PHY test pattern.
[How]
Add flag to indicate when link training is occuring.
Make workaround a no-op when flag is not set.
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: George Shen <George.Shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 44 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dc_link.h | 1 |
2 files changed, 26 insertions, 19 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index 86177577f7c7..81b0a01615c3 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -444,24 +444,26 @@ static void vendor_specific_lttpr_wa_one_two( struct dc_link *link, const uint8_t rate) { - uint8_t toggle_rate = 0x0; + if (link->apply_vendor_specific_lttpr_link_rate_wa) { + uint8_t toggle_rate = 0x0; - if (rate == 0x6) - toggle_rate = 0xA; - else - toggle_rate = 0x6; + if (rate == 0x6) + toggle_rate = 0xA; + else + toggle_rate = 0x6; - if (link->vendor_specific_lttpr_link_rate_wa == rate) { - /* W/A for certain LTTPR to reset internal state for link training */ - core_link_write_dpcd( - link, - DP_LINK_BW_SET, - &toggle_rate, - 1); - } + if (link->vendor_specific_lttpr_link_rate_wa == rate) { + /* W/A for certain LTTPR to reset internal state for link training */ + core_link_write_dpcd( + link, + DP_LINK_BW_SET, + &toggle_rate, + 1); + } - /* Store the last attempted link rate for this link */ - link->vendor_specific_lttpr_link_rate_wa = rate; + /* Store the last attempted link rate for this link */ + link->vendor_specific_lttpr_link_rate_wa = rate; + } } static void vendor_specific_lttpr_wa_three( @@ -2383,10 +2385,12 @@ enum link_training_result dc_link_dp_perform_link_training( /* reset previous training states */ if (link->dc->debug.apply_vendor_specific_lttpr_wa && (link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) && - link->lttpr_mode == LTTPR_MODE_TRANSPARENT) + link->lttpr_mode == LTTPR_MODE_TRANSPARENT) { + link->apply_vendor_specific_lttpr_link_rate_wa = true; vendor_specific_lttpr_wa_four(link, true); - else + } else { dpcd_exit_training_mode(link); + } /* configure link prior to entering training mode */ dpcd_configure_lttpr_mode(link, <_settings); @@ -2409,10 +2413,12 @@ enum link_training_result dc_link_dp_perform_link_training( /* exit training mode */ if (link->dc->debug.apply_vendor_specific_lttpr_wa && (link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) && - link->lttpr_mode == LTTPR_MODE_TRANSPARENT) + link->lttpr_mode == LTTPR_MODE_TRANSPARENT) { + link->apply_vendor_specific_lttpr_link_rate_wa = false; vendor_specific_lttpr_wa_four(link, (status != LINK_TRAINING_SUCCESS)); - else + } else { dpcd_exit_training_mode(link); + } /* switch to video idle */ if ((status == LINK_TRAINING_SUCCESS) || !skip_video_pattern) diff --git a/drivers/gpu/drm/amd/display/dc/dc_link.h b/drivers/gpu/drm/amd/display/dc/dc_link.h index ef123ab2e4b5..3d4f5bf049c3 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_link.h +++ b/drivers/gpu/drm/amd/display/dc/dc_link.h @@ -188,6 +188,7 @@ struct dc_link { /* Vendor specific LTTPR workaround variables */ uint8_t vendor_specific_lttpr_link_rate_wa; + bool apply_vendor_specific_lttpr_link_rate_wa; /* MST record stream using this link */ struct link_flags { |