drm/msm/dp: deinitialize mainlink if link training failed

DP compo phy have to be enable to start link training. When
link training failed phy need to be disabled so that next
link traning can be proceed smoothly at next plug in. This
patch de-initialize mainlink to disable phy if link training
failed. This prevent system crash due to
disp_cc_mdss_dp_link_intf_clk stuck at "off" state.  This patch
also perform checking power_on flag at dp_display_enable() and
dp_display_disable() to avoid crashing when unplug cable while
display is off.

Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 38 insertions, 2 deletions

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index aa40429cad42..139af85a8f2d 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1471,6 +1471,30 @@ static int dp_ctrl_reinitialize_mainlink(struct dp_ctrl_private *ctrl)
 	return ret;
 }
 
+static int dp_ctrl_deinitialize_mainlink(struct dp_ctrl_private *ctrl)
+{
+	struct dp_io *dp_io;
+	struct phy *phy;
+	int ret;
+
+	dp_io = &ctrl->parser->io;
+	phy = dp_io->phy;
+
+	dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, false);
+
+	dp_catalog_ctrl_reset(ctrl->catalog);
+
+	ret = dp_power_clk_enable(ctrl->power, DP_CTRL_PM, false);
+	if (ret) {
+		DRM_ERROR("Failed to disable link clocks. ret=%d\n", ret);
+	}
+
+	phy_power_off(phy);
+	phy_exit(phy);
+
+	return 0;
+}
+
 static int dp_ctrl_link_maintenance(struct dp_ctrl_private *ctrl)
 {
 	int ret = 0;
@@ -1651,8 +1675,7 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
 	if (rc)
 		return rc;
 
-	while (--link_train_max_retries &&
-		!atomic_read(&ctrl->dp_ctrl.aborted)) {
+	while (--link_train_max_retries) {
 		rc = dp_ctrl_reinitialize_mainlink(ctrl);
 		if (rc) {
 			DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n",
@@ -1667,6 +1690,10 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
 			break;
 		} else if (training_step == DP_TRAINING_1) {
 			/* link train_1 failed */
+			if (!dp_catalog_link_is_connected(ctrl->catalog)) {
+				break;
+			}
+
 			rc = dp_ctrl_link_rate_down_shift(ctrl);
 			if (rc < 0) { /* already in RBR = 1.6G */
 				if (cr.lane_0_1 & DP_LANE0_1_CR_DONE) {
@@ -1686,6 +1713,10 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
 			}
 		} else if (training_step == DP_TRAINING_2) {
 			/* link train_2 failed, lower lane rate */
+			if (!dp_catalog_link_is_connected(ctrl->catalog)) {
+				break;
+			}
+
 			rc = dp_ctrl_link_lane_down_shift(ctrl);
 			if (rc < 0) {
 				/* end with failure */
@@ -1706,6 +1737,11 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
 	 */
 	if (rc == 0)  /* link train successfully */
 		dp_ctrl_push_idle(dp_ctrl);
+	else  {
+		/* link training failed */
+		dp_ctrl_deinitialize_mainlink(ctrl);
+		rc = -ECONNRESET;
+	}
 
 	return rc;
 }