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  3. [PATCH v3 0/8] drm/msm/dp: Drop the HPD state machine
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[PATCH v3 8/8] drm/msm/dp: Add sink_count and link_ready to debug logs

Dmitry Baryshkov posted 8 patches 3 weeks, 3 days ago
[PATCH v3 8/8] drm/msm/dp: Add sink_count and link_ready to debug logs
Posted by Dmitry Baryshkov 3 weeks, 3 days ago 
From: Jessica Zhang <jessica.zhang@oss.qualcomm.com>

Add sink count and link_ready to the debug logs for [un]plug and HPD IRQ
handling.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index b26fba89e73a..67a193f58ce2 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -388,8 +388,10 @@ static int msm_dp_hpd_plug_handle(struct msm_dp_display_private *dp)
 	int ret;
 	struct platform_device *pdev = dp->msm_dp_display.pdev;
 
-	drm_dbg_dp(dp->drm_dev, "Before, type=%d\n",
-			dp->msm_dp_display.connector_type);
+	drm_dbg_dp(dp->drm_dev, "Before, type=%d sink_count=%d, link_ready=%d\n",
+			dp->msm_dp_display.connector_type,
+			dp->link->sink_count,
+			dp->msm_dp_display.link_ready);
 
 	if (dp->msm_dp_display.link_ready)
 		return 0;
@@ -411,8 +413,10 @@ static int msm_dp_hpd_plug_handle(struct msm_dp_display_private *dp)
 		pm_runtime_put_sync(&pdev->dev);
 	}
 
-	drm_dbg_dp(dp->drm_dev, "After, type=%d\n",
-			dp->msm_dp_display.connector_type);
+	drm_dbg_dp(dp->drm_dev, "After, type=%d sink_count=%d, link_ready=%d\n",
+			dp->msm_dp_display.connector_type,
+			dp->link->sink_count,
+			dp->msm_dp_display.link_ready);
 
 	/* uevent will complete connection part */
 	return 0;
@@ -440,8 +444,10 @@ static int msm_dp_hpd_unplug_handle(struct msm_dp_display_private *dp)
 
 	msm_dp_aux_enable_xfers(dp->aux, false);
 
-	drm_dbg_dp(dp->drm_dev, "Before, type=%d\n",
-			dp->msm_dp_display.connector_type);
+	drm_dbg_dp(dp->drm_dev, "Before, type=%d sink_count=%d, link_ready=%d\n",
+			dp->msm_dp_display.connector_type,
+			dp->link->sink_count,
+			dp->msm_dp_display.link_ready);
 
 	if (!dp->msm_dp_display.link_ready)
 		return 0;
@@ -465,8 +471,10 @@ static int msm_dp_hpd_unplug_handle(struct msm_dp_display_private *dp)
 	/* signal the disconnect event early to ensure proper teardown */
 	msm_dp_display_handle_plugged_change(&dp->msm_dp_display, false);
 
-	drm_dbg_dp(dp->drm_dev, "After, type=%d\n",
-			dp->msm_dp_display.connector_type);
+	drm_dbg_dp(dp->drm_dev, "After, type=%d, sink_count=%d, link_ready=%d\n",
+			dp->msm_dp_display.connector_type,
+			dp->link->sink_count,
+			dp->msm_dp_display.link_ready);
 
 	/* uevent will complete disconnection part */
 	pm_runtime_put_sync(&pdev->dev);
@@ -479,8 +487,10 @@ static int msm_dp_irq_hpd_handle(struct msm_dp_display_private *dp)
 	int rc = 0;
 
 	/* irq_hpd can happen at either connected or disconnected state */
-	drm_dbg_dp(dp->drm_dev, "Before, type=%d\n",
-			dp->msm_dp_display.connector_type);
+	drm_dbg_dp(dp->drm_dev, "Before, type=%d, sink_count=%d, link_ready=%d\n",
+			dp->msm_dp_display.connector_type,
+			dp->link->sink_count,
+			dp->msm_dp_display.link_ready);
 
 	/* check for any test request issued by sink */
 	rc = msm_dp_link_process_request(dp->link);
@@ -493,8 +503,10 @@ static int msm_dp_irq_hpd_handle(struct msm_dp_display_private *dp)
 			rc = msm_dp_display_handle_irq_hpd(dp);
 	}
 
-	drm_dbg_dp(dp->drm_dev, "After, type=%d\n",
-			dp->msm_dp_display.connector_type);
+	drm_dbg_dp(dp->drm_dev, "After, type=%d, sink_count=%d, link_ready=%d\n",
+			dp->msm_dp_display.connector_type,
+			dp->link->sink_count,
+			dp->msm_dp_display.link_ready);
 
 	return rc;
 }

-- 
2.47.3
Re: [PATCH v3 8/8] drm/msm/dp: Add sink_count and link_ready to debug logs
Posted by Bjorn Andersson 3 weeks, 2 days ago 
On Thu, Jan 15, 2026 at 09:29:13AM +0200, Dmitry Baryshkov wrote:
> From: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
> 
> Add sink count and link_ready to the debug logs for [un]plug and HPD IRQ
> handling.
> 

Reviewed-by: Bjorn Andersson <andersson@kernel.org>

Regards,
Bjorn

> Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 36 ++++++++++++++++++++++++------------
>  1 file changed, 24 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index b26fba89e73a..67a193f58ce2 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -388,8 +388,10 @@ static int msm_dp_hpd_plug_handle(struct msm_dp_display_private *dp)
>  	int ret;
>  	struct platform_device *pdev = dp->msm_dp_display.pdev;
>  
> -	drm_dbg_dp(dp->drm_dev, "Before, type=%d\n",
> -			dp->msm_dp_display.connector_type);
> +	drm_dbg_dp(dp->drm_dev, "Before, type=%d sink_count=%d, link_ready=%d\n",
> +			dp->msm_dp_display.connector_type,
> +			dp->link->sink_count,
> +			dp->msm_dp_display.link_ready);
>  
>  	if (dp->msm_dp_display.link_ready)
>  		return 0;
> @@ -411,8 +413,10 @@ static int msm_dp_hpd_plug_handle(struct msm_dp_display_private *dp)
>  		pm_runtime_put_sync(&pdev->dev);
>  	}
>  
> -	drm_dbg_dp(dp->drm_dev, "After, type=%d\n",
> -			dp->msm_dp_display.connector_type);
> +	drm_dbg_dp(dp->drm_dev, "After, type=%d sink_count=%d, link_ready=%d\n",
> +			dp->msm_dp_display.connector_type,
> +			dp->link->sink_count,
> +			dp->msm_dp_display.link_ready);
>  
>  	/* uevent will complete connection part */
>  	return 0;
> @@ -440,8 +444,10 @@ static int msm_dp_hpd_unplug_handle(struct msm_dp_display_private *dp)
>  
>  	msm_dp_aux_enable_xfers(dp->aux, false);
>  
> -	drm_dbg_dp(dp->drm_dev, "Before, type=%d\n",
> -			dp->msm_dp_display.connector_type);
> +	drm_dbg_dp(dp->drm_dev, "Before, type=%d sink_count=%d, link_ready=%d\n",
> +			dp->msm_dp_display.connector_type,
> +			dp->link->sink_count,
> +			dp->msm_dp_display.link_ready);
>  
>  	if (!dp->msm_dp_display.link_ready)
>  		return 0;
> @@ -465,8 +471,10 @@ static int msm_dp_hpd_unplug_handle(struct msm_dp_display_private *dp)
>  	/* signal the disconnect event early to ensure proper teardown */
>  	msm_dp_display_handle_plugged_change(&dp->msm_dp_display, false);
>  
> -	drm_dbg_dp(dp->drm_dev, "After, type=%d\n",
> -			dp->msm_dp_display.connector_type);
> +	drm_dbg_dp(dp->drm_dev, "After, type=%d, sink_count=%d, link_ready=%d\n",
> +			dp->msm_dp_display.connector_type,
> +			dp->link->sink_count,
> +			dp->msm_dp_display.link_ready);
>  
>  	/* uevent will complete disconnection part */
>  	pm_runtime_put_sync(&pdev->dev);
> @@ -479,8 +487,10 @@ static int msm_dp_irq_hpd_handle(struct msm_dp_display_private *dp)
>  	int rc = 0;
>  
>  	/* irq_hpd can happen at either connected or disconnected state */
> -	drm_dbg_dp(dp->drm_dev, "Before, type=%d\n",
> -			dp->msm_dp_display.connector_type);
> +	drm_dbg_dp(dp->drm_dev, "Before, type=%d, sink_count=%d, link_ready=%d\n",
> +			dp->msm_dp_display.connector_type,
> +			dp->link->sink_count,
> +			dp->msm_dp_display.link_ready);
>  
>  	/* check for any test request issued by sink */
>  	rc = msm_dp_link_process_request(dp->link);
> @@ -493,8 +503,10 @@ static int msm_dp_irq_hpd_handle(struct msm_dp_display_private *dp)
>  			rc = msm_dp_display_handle_irq_hpd(dp);
>  	}
>  
> -	drm_dbg_dp(dp->drm_dev, "After, type=%d\n",
> -			dp->msm_dp_display.connector_type);
> +	drm_dbg_dp(dp->drm_dev, "After, type=%d, sink_count=%d, link_ready=%d\n",
> +			dp->msm_dp_display.connector_type,
> +			dp->link->sink_count,
> +			dp->msm_dp_display.link_ready);
>  
>  	return rc;
>  }
> 
> -- 
> 2.47.3
> 
>

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