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* Re: [PATCH] drm/amdgpu: fix ref count leak in amdgpu_display_crtc_set_config
@ 2020-06-14 13:05 Markus Elfring
  0 siblings, 0 replies; 2+ messages in thread
From: Markus Elfring @ 2020-06-14 13:05 UTC (permalink / raw)
  To: Navid Emamdoost, amd-gfx, dri-devel
  Cc: Navid Emamdoost, Kangjie Lu, Stephen McCamant, Qiushi Wu,
	kernel-janitors, linux-kernel, Alex Deucher, Andrey Grodzovsky,
	Christian König, Shirish S, Daniel Vetter, David Airlie,
	Lyude Paul, Thomas Zimmermann, Yu Kuai

> in amdgpu_display_crtc_set_config, …

* Can the term “reference count” become relevant also for this commit message
  besides other possible adjustments?

* Can it be nicer to combine proposed updates for this software module
  as a patch series (with a cover letter)?

* Would you like to add the tag “Fixes”?


…
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> @@ -306,6 +306,7 @@  int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
>  		adev->have_disp_power_ref = false;
>  	}
>
> +out:
>  	/* drop the power reference we got coming in here */
>  	pm_runtime_put_autosuspend(dev->dev);
>  	return ret;

Perhaps use the label “put_runtime” instead?

Regards,
Markus

^ permalink raw reply	[flat|nested] 2+ messages in thread

* [PATCH] drm/amdgpu: fix ref count leak in amdgpu_display_crtc_set_config
@ 2020-06-14  7:09 Navid Emamdoost
  0 siblings, 0 replies; 2+ messages in thread
From: Navid Emamdoost @ 2020-06-14  7:09 UTC (permalink / raw)
  To: Alex Deucher, Christian König, David Airlie, Daniel Vetter,
	Andrey Grodzovsky, Lyude Paul, Thomas Zimmermann, Shirish S,
	yu kuai, Navid Emamdoost, amd-gfx, dri-devel, linux-kernel
  Cc: emamd001, wu000273, kjlu, smccaman

in amdgpu_display_crtc_set_config, the call to pm_runtime_get_sync
increments the counter even in case of failure, leading to incorrect
ref count. In case of failure, decrement the ref count before returning.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index f7143d927b6d..5e51f0acf744 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -282,7 +282,7 @@ int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
 
 	ret = pm_runtime_get_sync(dev->dev);
 	if (ret < 0)
-		return ret;
+		goto out;
 
 	ret = drm_crtc_helper_set_config(set, ctx);
 
@@ -297,7 +297,7 @@ int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
 	   take the current one */
 	if (active && !adev->have_disp_power_ref) {
 		adev->have_disp_power_ref = true;
-		return ret;
+		goto out;
 	}
 	/* if we have no active crtcs, then drop the power ref
 	   we got before */
@@ -306,6 +306,7 @@ int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
 		adev->have_disp_power_ref = false;
 	}
 
+out:
 	/* drop the power reference we got coming in here */
 	pm_runtime_put_autosuspend(dev->dev);
 	return ret;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

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2020-06-14 13:05 [PATCH] drm/amdgpu: fix ref count leak in amdgpu_display_crtc_set_config Markus Elfring
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2020-06-14  7:09 Navid Emamdoost

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