Intel_dp_check_link_status() function reads the Link status registers and returns a boolean to indicate link is good or bad. If the link is bad, it is retrained outside the function based on the return value.
Signed-off-by: Manasi Navare <[email protected]> --- drivers/gpu/drm/i915/intel_dp.c | 41 ++++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 6d586b7..c795c9e 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3863,7 +3863,7 @@ go_again: return -EINVAL; } -static void +static bool intel_dp_check_link_status(struct intel_dp *intel_dp) { struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base; @@ -3873,26 +3873,25 @@ intel_dp_check_link_status(struct intel_dp *intel_dp) WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); if (!intel_dp_get_link_status(intel_dp, link_status)) { - DRM_ERROR("Failed to get link status\n"); - return; + DRM_DEBUG_KMS("Failed to get link status\n"); + return false; } - if (!intel_encoder->base.crtc) - return; + /* Check if the link is valid by reading the bits of Link status + * registers + */ + if (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count) || + !drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) { + DRM_DEBUG_KMS("Channel EQ or CR not ok, need to retrain\n"); + return false; + } - if (!to_intel_crtc(intel_encoder->base.crtc)->active) - return; + DRM_DEBUG_KMS("Link is good, no need to retrain\n"); + return true; - /* if link training is requested we should perform it always */ - if ((intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) || - (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) { - DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n", - intel_encoder->base.name); - intel_dp_start_link_train(intel_dp); - intel_dp_stop_link_train(intel_dp); - } } + /* * According to DP spec * 5.1.2: @@ -3950,7 +3949,11 @@ intel_dp_short_pulse(struct intel_dp *intel_dp) } drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); - intel_dp_check_link_status(intel_dp); + if (!intel_dp_check_link_status(intel_dp) || + intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) { + intel_dp_start_link_train(intel_dp); + intel_dp_stop_link_train(intel_dp); + } drm_modeset_unlock(&dev->mode_config.connection_mutex); return true; @@ -4271,7 +4274,11 @@ intel_dp_long_pulse(struct intel_connector *intel_connector) * link loss triggerring long pulse!!!! */ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); - intel_dp_check_link_status(intel_dp); + if (!intel_dp_check_link_status(intel_dp) || + intel_dp->compliance_test_type == DP_TEST_LINK_TRAINING) { + intel_dp_start_link_train(intel_dp); + intel_dp_stop_link_train(intel_dp); + } drm_modeset_unlock(&dev->mode_config.connection_mutex); goto out; } -- 1.9.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
