diff options
| author | Martin Tsai <martin.tsai@amd.com> | 2020-07-15 11:21:43 +0800 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2020-08-06 16:38:32 -0400 |
| commit | 3fd20292c2352660155bbc11736dd014b2fc6e98 (patch) | |
| tree | 17c160b13191a6a5a3e2492f31cbf550a693f6d2 /drivers/gpu | |
| parent | bc0cd80783ff7c2201b44d384bab4629c9cb7db9 (diff) | |
drm/amd/display: Check lane status again after link training done
[Why]
Some monitors could suffer symbol unlock but cannot send HPD IRQ to
notic source device to handle link loss. This makes monitor stuck in
abnormal status and causes black screen.
[How]
According to the suggestion from scalar vendor, to check lane status
again after link training done. That can improve the comaptibility
from current production monitors.
Signed-off-by: Martin Tsai <martin.tsai@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Eryk Brol <eryk.brol@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 50 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/include/link_service_types.h | 2 |
2 files changed, 52 insertions, 0 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 5cb7b834e459..1a3dbed3becb 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 @@ -1133,6 +1133,45 @@ static inline enum link_training_result perform_link_training_int( return status; } +static enum link_training_result check_link_loss_status( + struct dc_link *link, + const struct link_training_settings *link_training_setting) +{ + enum link_training_result status = LINK_TRAINING_SUCCESS; + unsigned int lane01_status_address = DP_LANE0_1_STATUS; + union lane_status lane_status; + uint8_t dpcd_buf[4] = {0}; + uint32_t lane; + + core_link_read_dpcd( + link, + lane01_status_address, + (uint8_t *)(dpcd_buf), + sizeof(dpcd_buf)); + + /*parse lane status*/ + for (lane = 0; lane < link->cur_link_settings.lane_count; lane++) { + /* + * check lanes status + */ + lane_status.raw = get_nibble_at_index(&dpcd_buf[0], lane); + + if (!lane_status.bits.CHANNEL_EQ_DONE_0 || + !lane_status.bits.CR_DONE_0 || + !lane_status.bits.SYMBOL_LOCKED_0) { + /* if one of the channel equalization, clock + * recovery or symbol lock is dropped + * consider it as (link has been + * dropped) dp sink status has changed + */ + status = LINK_TRAINING_LINK_LOSS; + break; + } + } + + return status; +} + static void initialize_training_settings( struct dc_link *link, const struct dc_link_settings *link_setting, @@ -1372,6 +1411,9 @@ static void print_status_message( case LINK_TRAINING_LQA_FAIL: lt_result = "LQA failed"; break; + case LINK_TRAINING_LINK_LOSS: + lt_result = "Link loss"; + break; default: break; } @@ -1531,6 +1573,14 @@ enum link_training_result dc_link_dp_perform_link_training( status); } + /* delay 5ms after Main Link output idle pattern and then check + * DPCD 0202h. + */ + if (link->connector_signal != SIGNAL_TYPE_EDP && status == LINK_TRAINING_SUCCESS) { + msleep(5); + status = check_link_loss_status(link, <_settings); + } + /* 6. print status message*/ print_status_message(link, <_settings, status); diff --git a/drivers/gpu/drm/amd/display/include/link_service_types.h b/drivers/gpu/drm/amd/display/include/link_service_types.h index 4869d4562e4d..550f46e9b95f 100644 --- a/drivers/gpu/drm/amd/display/include/link_service_types.h +++ b/drivers/gpu/drm/amd/display/include/link_service_types.h @@ -66,6 +66,8 @@ enum link_training_result { /* other failure during EQ step */ LINK_TRAINING_EQ_FAIL_EQ, LINK_TRAINING_LQA_FAIL, + /* one of the CR,EQ or symbol lock is dropped */ + LINK_TRAINING_LINK_LOSS, }; struct link_training_settings { |