[PATCH 8/8] drm/i915/dp: Protect link training with connection mutex

[Dhinakaran Pandiyan]

The other instances of link training are protected with
connection_mutex, so do the same in check_mst_status() too.

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index aab9ba31f79e..644463ba313e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4191,6 +4191,7 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
 static int
 intel_dp_check_mst_status(struct intel_dp *intel_dp)
 {
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 	bool bret;
 	u8 esi[DP_DPRX_ESI_LEN] = { 0 };
 	int ret = 0;
@@ -4205,8 +4206,11 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
 		if (intel_dp->active_mst_links &&
 		    !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) {
 			DRM_DEBUG_KMS("channel EQ not ok, retraining\n");
+
+			drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 			intel_dp_start_link_train(intel_dp);
 			intel_dp_stop_link_train(intel_dp);
+			drm_modeset_unlock(&dev->mode_config.connection_mutex);
 		}
 
 		DRM_DEBUG_KMS("got esi %3ph\n", esi);
-- 
2.11.0