[PATCH 0/2] drm/msm/dp: fix runtime PM leaks on hotplug

[PATCH 0/2] drm/msm/dp: fix runtime PM leaks on hotplug

[Johan Hovold]

As I've reported elsewhere, I've been hitting runtime PM usage count
leaks when investigated a DisplayPort hotplug regression on the Lenovo
ThinkPad X13s. [1]

This series addresses two obvious leaks on disconnect and on connect
failures, respectively.

Johan


[1] https://lore.kernel.org/lkml/Ze8Ke_M2xHyPYCu-@hovoldconsulting.com/


Johan Hovold (2):
  drm/msm/dp: fix runtime PM leak on disconnect
  drm/msm/dp: fix runtime PM leak on connect failure

 drivers/gpu/drm/msm/dp/dp_display.c | 2 ++
 1 file changed, 2 insertions(+)

-- 
2.43.2

[PATCH 1/2] drm/msm/dp: fix runtime PM leak on disconnect

[Johan Hovold]

Make sure to put the runtime PM usage count (and suspend) also when
receiving a disconnect event while in the ST_MAINLINK_READY state.

This specifically avoids leaking a runtime PM usage count on every
disconnect with display servers that do not automatically enable
external displays when receiving a hotplug notification.

Fixes: 5814b8bf086a ("drm/msm/dp: incorporate pm_runtime framework into DP driver")
Cc: stable@vger.kernel.org      # 6.8
Cc: Kuogee Hsieh <quic_khsieh@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 4c72124ffb5d..8e8cf531da45 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -655,6 +655,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
 		dp_display_host_phy_exit(dp);
 		dp->hpd_state = ST_DISCONNECTED;
 		dp_display_notify_disconnect(&dp->dp_display.pdev->dev);
+		pm_runtime_put_sync(&pdev->dev);
 		mutex_unlock(&dp->event_mutex);
 		return 0;
 	}
-- 
2.43.2

[PATCH 2/2] drm/msm/dp: fix runtime PM leak on connect failure

[Johan Hovold]

Make sure to balance the runtime PM usage counter (and suspend) before
returning on connect failures (e.g. DPCD read failures after a spurious
connect event or if link training fails).

Fixes: 5814b8bf086a ("drm/msm/dp: incorporate pm_runtime framework into DP driver")
Cc: stable@vger.kernel.org      # 6.8
Cc: Kuogee Hsieh <quic_khsieh@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 8e8cf531da45..78464c395c3d 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -598,6 +598,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
 	ret = dp_display_usbpd_configure_cb(&pdev->dev);
 	if (ret) {	/* link train failed */
 		dp->hpd_state = ST_DISCONNECTED;
+		pm_runtime_put_sync(&pdev->dev);
 	} else {
 		dp->hpd_state = ST_MAINLINK_READY;
 	}
-- 
2.43.2

Re: [PATCH 2/2] drm/msm/dp: fix runtime PM leak on connect failure

[Abhinav Kumar]

On 3/13/2024 9:43 AM, Johan Hovold wrote:
> Make sure to balance the runtime PM usage counter (and suspend) before
> returning on connect failures (e.g. DPCD read failures after a spurious
> connect event or if link training fails).
> 
> Fixes: 5814b8bf086a ("drm/msm/dp: incorporate pm_runtime framework into DP driver")
> Cc: stable@vger.kernel.org      # 6.8
> Cc: Kuogee Hsieh <quic_khsieh@quicinc.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

Re: [PATCH 1/2] drm/msm/dp: fix runtime PM leak on disconnect

[Abhinav Kumar]

On 3/13/2024 9:43 AM, Johan Hovold wrote:
> Make sure to put the runtime PM usage count (and suspend) also when
> receiving a disconnect event while in the ST_MAINLINK_READY state.
> 
> This specifically avoids leaking a runtime PM usage count on every
> disconnect with display servers that do not automatically enable
> external displays when receiving a hotplug notification.
> 

Thanks for the fixes. Both look right to me.

I will pick up both of them for -fixes

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>



> Fixes: 5814b8bf086a ("drm/msm/dp: incorporate pm_runtime framework into DP driver")
> Cc: stable@vger.kernel.org      # 6.8
> Cc: Kuogee Hsieh <quic_khsieh@quicinc.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/gpu/drm/msm/dp/dp_display.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 4c72124ffb5d..8e8cf531da45 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -655,6 +655,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
>   		dp_display_host_phy_exit(dp);
>   		dp->hpd_state = ST_DISCONNECTED;
>   		dp_display_notify_disconnect(&dp->dp_display.pdev->dev);
> +		pm_runtime_put_sync(&pdev->dev);
>   		mutex_unlock(&dp->event_mutex);
>   		return 0;
>   	}

Re: [PATCH 0/2] drm/msm/dp: fix runtime PM leaks on hotplug

[Abhinav Kumar]

On Wed, 13 Mar 2024 17:43:04 +0100, Johan Hovold wrote:
> As I've reported elsewhere, I've been hitting runtime PM usage count
> leaks when investigated a DisplayPort hotplug regression on the Lenovo
> ThinkPad X13s. [1]
> 
> This series addresses two obvious leaks on disconnect and on connect
> failures, respectively.
> 
> [...]

Applied, thanks!

[1/2] drm/msm/dp: fix runtime PM leak on disconnect
      https://gitlab.freedesktop.org/drm/msm/-/commit/0640f47b7426
[2/2] drm/msm/dp: fix runtime PM leak on connect failure
      https://gitlab.freedesktop.org/drm/msm/-/commit/e86750b01a15      

Best regards,
-- 
Abhinav Kumar <quic_abhinavk@quicinc.com>