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* [PATCH v2 3/3] drm/msm/dp: check main link status before start aux read
@ 2021-04-13 23:11 Kuogee Hsieh
  2021-04-14 21:09 ` Stephen Boyd
  0 siblings, 1 reply; 10+ messages in thread
From: Kuogee Hsieh @ 2021-04-13 23:11 UTC (permalink / raw)
  To: robdclark, sean, swboyd
  Cc: tanmay, abhinavk, aravindh, khsieh, airlied, daniel,
	linux-arm-msm, dri-devel, freedreno, linux-kernel

Make sure main link is in connection state before start aux
read/write operation to avoid unnecessary long delay due to
main link had been unplugged.

Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
---
 drivers/gpu/drm/msm/dp/dp_aux.c  |  5 +++++
 drivers/gpu/drm/msm/dp/dp_link.c | 20 +++++++++++++++-----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index 7c22bfe..fae3806 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -343,6 +343,11 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
 
 	mutex_lock(&aux->mutex);
 
+	if (!dp_catalog_link_is_connected(aux->catalog)) {
+		ret = -ETIMEDOUT;
+		goto unlock_exit;
+	}
+
 	aux->native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
 
 	/* Ignore address only message */
diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index be986da..d35b18e 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -737,18 +737,25 @@ static int dp_link_parse_sink_count(struct dp_link *dp_link)
 	return 0;
 }
 
-static void dp_link_parse_sink_status_field(struct dp_link_private *link)
+static int dp_link_parse_sink_status_field(struct dp_link_private *link)
 {
 	int len = 0;
 
 	link->prev_sink_count = link->dp_link.sink_count;
-	dp_link_parse_sink_count(&link->dp_link);
+	len = dp_link_parse_sink_count(&link->dp_link);
+	if (len < 0) {
+		DRM_ERROR("DP lparse sink count failed\n");
+		return len;
+	}
 
 	len = drm_dp_dpcd_read_link_status(link->aux,
 		link->link_status);
-	if (len < DP_LINK_STATUS_SIZE)
+	if (len < DP_LINK_STATUS_SIZE) {
 		DRM_ERROR("DP link status read failed\n");
-	dp_link_parse_request(link);
+		return len;
+	}
+
+	return dp_link_parse_request(link);
 }
 
 /**
@@ -1032,7 +1039,10 @@ int dp_link_process_request(struct dp_link *dp_link)
 
 	dp_link_reset_data(link);
 
-	dp_link_parse_sink_status_field(link);
+	ret = dp_link_parse_sink_status_field(link);
+	if (ret) {
+		return ret;
+	}
 
 	if (link->request.test_requested == DP_TEST_LINK_EDID_READ) {
 		dp_link->sink_request |= DP_TEST_LINK_EDID_READ;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH v3 3/3] drm/msm/dp: check main link status before start aux read
@ 2021-04-16 17:38 Kuogee Hsieh
  2021-04-20 23:38 ` Stephen Boyd
  0 siblings, 1 reply; 10+ messages in thread
From: Kuogee Hsieh @ 2021-04-16 17:38 UTC (permalink / raw)
  To: robdclark, sean, swboyd
  Cc: abhinavk, aravindh, khsieh, airlied, daniel, linux-arm-msm,
	dri-devel, freedreno, linux-kernel

Maybe when the cable is disconnected the DP phy should be shutdown and
some bit in the phy could effectively "cut off" the aux channel and then
NAKs would start coming through here in the DP controller I/O register
space. This patch have DP aux channel read/write to return NAK immediately
if DP controller connection status is in unplugged state.

Changes in V3:
-- check core_initialized before handle irq_hpd
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
---
 drivers/gpu/drm/msm/dp/dp_aux.c     |  5 +++++
 drivers/gpu/drm/msm/dp/dp_display.c | 14 ++++++++++----
 drivers/gpu/drm/msm/dp/dp_link.c    | 20 +++++++++++++++-----
 3 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index 7c22bfe..fae3806 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -343,6 +343,11 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
 
 	mutex_lock(&aux->mutex);
 
+	if (!dp_catalog_link_is_connected(aux->catalog)) {
+		ret = -ETIMEDOUT;
+		goto unlock_exit;
+	}
+
 	aux->native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
 
 	/* Ignore address only message */
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 1784e11..db3f45e 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -571,7 +571,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
 		dp->hpd_state = ST_DISCONNECTED;
 
 		if (ret == -ECONNRESET) { /* cable unplugged */
-			dp->core_initialized = false;
+			DRM_ERROR("dongle unplugged = %d\n", ret);
 		}
 
 	} else {
@@ -711,9 +711,15 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
 		return 0;
 	}
 
-	ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
-	if (ret == -ECONNRESET) { /* cable unplugged */
-		dp->core_initialized = false;
+	/*
+	 * dp core (ahb/aux clks) must be initialized before
+	 * irq_hpd be handled
+	 */
+	if (dp->core_initialized) {
+		ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
+		if (ret == -ECONNRESET) { /* cable unplugged */
+			DRM_ERROR("dongle unplugged = %d\n", ret);
+		}
 	}
 
 	mutex_unlock(&dp->event_mutex);
diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index be986da..53ecae6 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -737,18 +737,25 @@ static int dp_link_parse_sink_count(struct dp_link *dp_link)
 	return 0;
 }
 
-static void dp_link_parse_sink_status_field(struct dp_link_private *link)
+static int dp_link_parse_sink_status_field(struct dp_link_private *link)
 {
 	int len = 0;
 
 	link->prev_sink_count = link->dp_link.sink_count;
-	dp_link_parse_sink_count(&link->dp_link);
+	len = dp_link_parse_sink_count(&link->dp_link);
+	if (len < 0) {
+		DRM_ERROR("DP parse sink count failed\n");
+		return len;
+	}
 
 	len = drm_dp_dpcd_read_link_status(link->aux,
 		link->link_status);
-	if (len < DP_LINK_STATUS_SIZE)
+	if (len < DP_LINK_STATUS_SIZE) {
 		DRM_ERROR("DP link status read failed\n");
-	dp_link_parse_request(link);
+		return len;
+	}
+
+	return dp_link_parse_request(link);
 }
 
 /**
@@ -1032,7 +1039,10 @@ int dp_link_process_request(struct dp_link *dp_link)
 
 	dp_link_reset_data(link);
 
-	dp_link_parse_sink_status_field(link);
+	ret = dp_link_parse_sink_status_field(link);
+	if (ret) {
+		return ret;
+	}
 
 	if (link->request.test_requested == DP_TEST_LINK_EDID_READ) {
 		dp_link->sink_request |= DP_TEST_LINK_EDID_READ;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply related	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2021-04-21 17:43 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-13 23:11 [PATCH v2 3/3] drm/msm/dp: check main link status before start aux read Kuogee Hsieh
2021-04-14 21:09 ` Stephen Boyd
2021-04-15 17:37   ` khsieh
2021-04-15 20:06     ` Stephen Boyd
2021-04-15 22:02       ` khsieh
2021-04-15 22:46         ` Stephen Boyd
2021-04-15 23:28           ` [PATCH v3 " Kuogee Hsieh
2021-04-16 17:38 Kuogee Hsieh
2021-04-20 23:38 ` Stephen Boyd
2021-04-21 17:43   ` khsieh

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