Check to make sure the transaction succeeded before
using the register value. Fixes occasional link training
problems.
Noticed-by: Sergei Antonov <saproj at gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
drivers/gpu/drm/radeon/atombios_dp.c | 44 ++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
b/drivers/gpu/drm/radeon/atombios_dp.c
index bc0119f..54e4f52 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;
--
1.8.3.1
