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| author | Alex Deucher <alexdeucher@gmail.com> | 2014-04-30 09:27:15 -0400 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2014-05-01 12:28:09 +0200 |
| commit | aa019b791a3e138ca0eaa38e72b4ea97d482a7bc (patch) | |
| tree | c410500d6aae5314a2be50196d1e9efb687144a8 /drivers | |
| parent | 3b333c55485fef0089ae7398906599d000df195e (diff) | |
| download | linux-aa019b791a3e138ca0eaa38e72b4ea97d482a7bc.tar.gz linux-aa019b791a3e138ca0eaa38e72b4ea97d482a7bc.tar.bz2 linux-aa019b791a3e138ca0eaa38e72b4ea97d482a7bc.zip | |
drm/radeon/dp: check for errors in dpcd reads
Check to make sure the transaction succeeded before
using the register value. Fixes occasional link training
problems.
Noticed-by: Sergei Antonov <saproj@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/radeon/atombios_dp.c | 44 |
1 files changed, 25 insertions, 19 deletions
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index bc0119fb6c12..54e4f52549af 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -366,11 +366,11 @@ static void radeon_dp_probe_oui(struct radeon_connector *radeon_connector) if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT)) return; - if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3)) + if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_SINK_OUI, buf, 3) == 3) DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n", buf[0], buf[1], buf[2]); - if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3)) + if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_BRANCH_OUI, buf, 3) == 3) DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n", buf[0], buf[1], buf[2]); } @@ -419,21 +419,23 @@ int radeon_dp_get_panel_mode(struct drm_encoder *encoder, if (dp_bridge != ENCODER_OBJECT_ID_NONE) { /* DP bridge chips */ - drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, - DP_EDP_CONFIGURATION_CAP, &tmp); - if (tmp & 1) - panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; - else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) || - (dp_bridge == ENCODER_OBJECT_ID_TRAVIS)) - panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE; - else - panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE; + if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, + DP_EDP_CONFIGURATION_CAP, &tmp) == 1) { + if (tmp & 1) + panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; + else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) || + (dp_bridge == ENCODER_OBJECT_ID_TRAVIS)) + panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE; + else + panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE; + } } else if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) { /* eDP */ - drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, - DP_EDP_CONFIGURATION_CAP, &tmp); - if (tmp & 1) - panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; + if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, + DP_EDP_CONFIGURATION_CAP, &tmp) == 1) { + if (tmp & 1) + panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; + } } return panel_mode; @@ -809,11 +811,15 @@ void radeon_dp_link_train(struct drm_encoder *encoder, else dp_info.enc_id |= ATOM_DP_CONFIG_LINK_A; - drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp); - if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED)) - dp_info.tp3_supported = true; - else + if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, DP_MAX_LANE_COUNT, &tmp) + == 1) { + if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED)) + dp_info.tp3_supported = true; + else + dp_info.tp3_supported = false; + } else { dp_info.tp3_supported = false; + } memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE); dp_info.rdev = rdev; |