Merge "msm: mdss: dp: fix no display issues during cable plugin/plugouts"

2 files changed, 79 insertions, 12 deletions

diff --git a/drivers/video/fbdev/msm/mdss_dp.c b/drivers/video/fbdev/msm/mdss_dp.c
index 6b003239ed34..71584dff75cb 100644
--- a/drivers/video/fbdev/msm/mdss_dp.c
+++ b/drivers/video/fbdev/msm/mdss_dp.c
@@ -1568,6 +1568,19 @@ static int mdss_dp_on_irq(struct mdss_dp_drv_pdata *dp_drv, bool lt_needed)
 {
 	int ret = 0;
 	char ln_map[4];
+	bool connected;
+
+	mutex_lock(&dp_drv->attention_lock);
+	connected = dp_drv->cable_connected;
+	mutex_unlock(&dp_drv->attention_lock);
+
+	/*
+	 * If DP cable disconnected, Avoid link training or turning on DP Path
+	 */
+	if (!connected) {
+		pr_err("DP sink not connected\n");
+		return -EINVAL;
+	}
 
 	/* wait until link training is completed */
 	pr_debug("enter, lt_needed=%s\n", lt_needed ? "true" : "false");
@@ -1609,6 +1622,13 @@ static int mdss_dp_on_irq(struct mdss_dp_drv_pdata *dp_drv, bool lt_needed)
 		dp_drv->power_on = true;
 
 		ret = mdss_dp_setup_main_link(dp_drv, lt_needed);
+		if (ret) {
+			if (ret == -ENODEV || ret == -EINVAL) {
+				pr_err("main link setup failed\n");
+				mutex_unlock(&dp_drv->train_mutex);
+				return ret;
+			}
+		}
 
 exit_loop:
 		mutex_unlock(&dp_drv->train_mutex);
@@ -2209,7 +2229,7 @@ static int mdss_dp_process_hpd_high(struct mdss_dp_drv_pdata *dp)
 	ret = mdss_dp_dpcd_cap_read(dp);
 	if (ret || !mdss_dp_aux_is_link_rate_valid(dp->dpcd.max_link_rate) ||
 		!mdss_dp_aux_is_lane_count_valid(dp->dpcd.max_lane_count)) {
-		if (ret == EDP_AUX_ERR_TOUT) {
+		if ((ret == -ENODEV) || (ret == EDP_AUX_ERR_TOUT)) {
 			pr_err("DPCD read timedout, skip connect notification\n");
 			goto end;
 		}
@@ -2241,6 +2261,9 @@ static int mdss_dp_process_hpd_high(struct mdss_dp_drv_pdata *dp)
 read_edid:
 	ret = mdss_dp_edid_read(dp);
 	if (ret) {
+		if (ret == -ENODEV)
+			goto end;
+
 		pr_err("edid read error, setting default resolution\n");
 		goto notify;
 	}
@@ -3558,9 +3581,33 @@ static void mdss_dp_reset_event_list(struct mdss_dp_drv_pdata *dp)
 
 static void mdss_dp_reset_sw_state(struct mdss_dp_drv_pdata *dp)
 {
+	int ret = 0;
+
 	pr_debug("enter\n");
 	mdss_dp_reset_event_list(dp);
+
+	/*
+	 * IRQ_HPD attention event handler first turns on DP path and then
+	 * notifies CONNECT_IRQ_HPD and waits for userspace to trigger UNBLANK.
+	 * In such cases, before UNBLANK call, if cable is disconnected, if
+	 * DISCONNECT is notified immediately, userspace might not sense any
+	 * change in connection status, leaving DP controller ON.
+	 *
+	 * To avoid such cases, wait for the connection event to complete before
+	 * sending disconnection event
+	 */
+	if (atomic_read(&dp->notification_pending)) {
+		pr_debug("waiting for the pending notitfication\n");
+		ret = wait_for_completion_timeout(&dp->notification_comp, HZ);
+		if (ret <= 0) {
+			pr_err("%s timed out\n",
+				mdss_dp_notification_status_to_string(
+					dp->hpd_notification_status));
+		}
+	}
+
 	atomic_set(&dp->notification_pending, 0);
+	/* complete any waiting completions */
 	complete_all(&dp->notification_comp);
 }
 
diff --git a/drivers/video/fbdev/msm/mdss_dp_aux.c b/drivers/video/fbdev/msm/mdss_dp_aux.c
index 86946adfeeb0..407f230ca71e 100644
--- a/drivers/video/fbdev/msm/mdss_dp_aux.c
+++ b/drivers/video/fbdev/msm/mdss_dp_aux.c
@@ -411,7 +411,8 @@ retry:
 
 		if (!connected) {
 			pr_err("dp cable disconnected\n");
-			break;
+			ret = -ENODEV;
+			goto end;
 		}
 
 		dp->aux_error_num = EDP_AUX_ERR_NONE;
@@ -877,7 +878,7 @@ void dp_extract_edid_detailed_timing_description(struct edp_edid *edid,
 
 static int dp_aux_chan_ready(struct mdss_dp_drv_pdata *ep)
 {
-	int cnt, ret;
+	int cnt, ret = 0;
 	char data = 0;
 
 	for (cnt = 5; cnt; cnt--) {
@@ -886,6 +887,10 @@ static int dp_aux_chan_ready(struct mdss_dp_drv_pdata *ep)
 				ret, mdss_dp_get_aux_error(ep->aux_error_num));
 		if (ret >= 0)
 			break;
+
+		if (ret == -ENODEV)
+			return ret;
+
 		msleep(100);
 	}
 
@@ -973,6 +978,7 @@ int mdss_dp_edid_read(struct mdss_dp_drv_pdata *dp)
 	u32 checksum = 0;
 	bool phy_aux_update_requested = false;
 	bool ext_block_parsing_done = false;
+	bool connected = false;
 
 	ret = dp_aux_chan_ready(dp);
 	if (ret) {
@@ -992,6 +998,15 @@ int mdss_dp_edid_read(struct mdss_dp_drv_pdata *dp)
 		u8 segment;
 		u8 edid_buf[EDID_BLOCK_SIZE] = {0};
 
+		mutex_lock(&dp->attention_lock);
+		connected = dp->cable_connected;
+		mutex_unlock(&dp->attention_lock);
+
+		if (!connected) {
+			pr_err("DP sink not connected\n");
+			return -ENODEV;
+		}
+
 		/*
 		 * Write the segment first.
 		 * Segment = 0, for blocks 0 and 1
@@ -1243,7 +1258,7 @@ int mdss_dp_aux_link_status_read(struct mdss_dp_drv_pdata *ep, int len)
 	rlen = dp_aux_read_buf(ep, 0x202, len, 0);
 	if (rlen < len) {
 		pr_err("edp aux read failed\n");
-		return 0;
+		return rlen;
 	}
 	rp = &ep->rxp;
 	bp = rp->data;
@@ -2459,21 +2474,24 @@ static int dp_start_link_train_1(struct mdss_dp_drv_pdata *ep)
 		usleep_time = ep->dpcd.training_read_interval;
 		usleep_range(usleep_time, usleep_time);
 
-		mdss_dp_aux_link_status_read(ep, 6);
+		ret = mdss_dp_aux_link_status_read(ep, 6);
+		if (ret == -ENODEV)
+			break;
+
 		if (mdss_dp_aux_clock_recovery_done(ep)) {
 			ret = 0;
 			break;
 		}
 
 		if (ep->v_level == DPCD_LINK_VOLTAGE_MAX) {
-			ret = -1;
+			ret = -EAGAIN;
 			break;	/* quit */
 		}
 
 		if (old_v_level == ep->v_level) {
 			tries++;
 			if (tries >= maximum_retries) {
-				ret = -1;
+				ret = -EAGAIN;
 				break;	/* quit */
 			}
 		} else {
@@ -2511,7 +2529,9 @@ static int dp_start_link_train_2(struct mdss_dp_drv_pdata *ep)
 		usleep_time = ep->dpcd.training_read_interval;
 		usleep_range(usleep_time, usleep_time);
 
-		mdss_dp_aux_link_status_read(ep, 6);
+		ret = mdss_dp_aux_link_status_read(ep, 6);
+		if (ret == -ENODEV)
+			break;
 
 		if (mdss_dp_aux_channel_eq_done(ep)) {
 			ret = 0;
@@ -2519,7 +2539,7 @@ static int dp_start_link_train_2(struct mdss_dp_drv_pdata *ep)
 		}
 
 		if (tries > maximum_retries) {
-			ret = -1;
+			ret = -EAGAIN;
 			break;
 		}
 		tries++;
@@ -2584,7 +2604,7 @@ int mdss_dp_link_train(struct mdss_dp_drv_pdata *dp)
 
 	ret = dp_start_link_train_1(dp);
 	if (ret < 0) {
-		if (!dp_link_rate_down_shift(dp)) {
+		if ((ret == -EAGAIN) && !dp_link_rate_down_shift(dp)) {
 			pr_debug("retry with lower rate\n");
 			dp_clear_training_pattern(dp);
 			return -EAGAIN;
@@ -2603,7 +2623,7 @@ int mdss_dp_link_train(struct mdss_dp_drv_pdata *dp)
 
 	ret = dp_start_link_train_2(dp);
 	if (ret < 0) {
-		if (!dp_link_rate_down_shift(dp)) {
+		if ((ret == -EAGAIN) && !dp_link_rate_down_shift(dp)) {
 			pr_debug("retry with lower rate\n");
 			dp_clear_training_pattern(dp);
 			return -EAGAIN;
@@ -2640,7 +2660,7 @@ int mdss_dp_dpcd_status_read(struct mdss_dp_drv_pdata *ep)
 
 	ret = mdss_dp_aux_link_status_read(ep, 6);
 
-	if (ret) {
+	if (ret > 0) {
 		sp = &ep->link_status;
 		ret = sp->port_0_in_sync; /* 1 == sync */
 	}