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* [PATCH] drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume
@ 2021-10-02 15:18 Guchun Chen
  2021-10-04 16:04 ` Andrey Grodzovsky
  0 siblings, 1 reply; 3+ messages in thread
From: Guchun Chen @ 2021-10-02 15:18 UTC (permalink / raw)
  To: amd-gfx, christian.koenig, xinhui.pan, alexander.deucher,
	andrey.grodzovsky, monk.liu
  Cc: Guchun Chen

In current code, when a PCI error state pci_channel_io_normal is detectd,
it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI
driver will continue the execution of PCI resume callback report_resume by
pci_walk_bridge, and the callback will go into amdgpu_pci_resume
finally, where write lock is releasd unconditionally without acquiring
such lock first. In this case, a deadlock will happen when other threads
start to acquire the read lock.

To fix this, add a member in amdgpu_device strucutre to cache
pci_channel_state, and only continue the execution in amdgpu_pci_resume
when it's pci_channel_io_frozen.

Fixes: c9a6b82f45e2("drm/amdgpu: Implement DPC recovery")
Suggested-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index f4bceb2624fb..720d0ccecfe0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1094,6 +1094,7 @@ struct amdgpu_device {
 
 	bool                            no_hw_access;
 	struct pci_saved_state          *pci_state;
+	pci_channel_state_t		cached_state;
 
 	struct amdgpu_reset_control     *reset_cntl;
 	uint32_t                        ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index bb5ad2b6ca13..1aaeb4b30edc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -5368,6 +5368,8 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta
 		return PCI_ERS_RESULT_DISCONNECT;
 	}
 
+	adev->cached_state = state;
+
 	switch (state) {
 	case pci_channel_io_normal:
 		return PCI_ERS_RESULT_CAN_RECOVER;
@@ -5510,6 +5512,10 @@ void amdgpu_pci_resume(struct pci_dev *pdev)
 
 	DRM_INFO("PCI error: resume callback!!\n");
 
+	/* Only continue execution for the case of pci_channel_io_frozen */
+	if (adev->cached_state != pci_channel_io_frozen)
+		return;
+
 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
 		struct amdgpu_ring *ring = adev->rings[i];
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume
  2021-10-02 15:18 [PATCH] drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume Guchun Chen
@ 2021-10-04 16:04 ` Andrey Grodzovsky
  2021-10-05 11:43   ` Chen, Guchun
  0 siblings, 1 reply; 3+ messages in thread
From: Andrey Grodzovsky @ 2021-10-04 16:04 UTC (permalink / raw)
  To: Guchun Chen, amd-gfx, christian.koenig, xinhui.pan,
	alexander.deucher, monk.liu


On 2021-10-02 11:18 a.m., Guchun Chen wrote:
> In current code, when a PCI error state pci_channel_io_normal is detectd,
> it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI
> driver will continue the execution of PCI resume callback report_resume by
> pci_walk_bridge, and the callback will go into amdgpu_pci_resume
> finally, where write lock is releasd unconditionally without acquiring
> such lock first. In this case, a deadlock will happen when other threads
> start to acquire the read lock.
>
> To fix this, add a member in amdgpu_device strucutre to cache
> pci_channel_state, and only continue the execution in amdgpu_pci_resume
> when it's pci_channel_io_frozen.
>
> Fixes: c9a6b82f45e2("drm/amdgpu: Implement DPC recovery")
> Suggested-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
> Signed-off-by: Guchun Chen <guchun.chen@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 ++++++
>   2 files changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index f4bceb2624fb..720d0ccecfe0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1094,6 +1094,7 @@ struct amdgpu_device {
>   
>   	bool                            no_hw_access;
>   	struct pci_saved_state          *pci_state;
> +	pci_channel_state_t		cached_state;


I would give a more descriptive name to this (e.g. pci_channel_state)
Other then that Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>

Andrey


>   
>   	struct amdgpu_reset_control     *reset_cntl;
>   	uint32_t                        ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index bb5ad2b6ca13..1aaeb4b30edc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5368,6 +5368,8 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta
>   		return PCI_ERS_RESULT_DISCONNECT;
>   	}
>   
> +	adev->cached_state = state;
> +
>   	switch (state) {
>   	case pci_channel_io_normal:
>   		return PCI_ERS_RESULT_CAN_RECOVER;
> @@ -5510,6 +5512,10 @@ void amdgpu_pci_resume(struct pci_dev *pdev)
>   
>   	DRM_INFO("PCI error: resume callback!!\n");
>   
> +	/* Only continue execution for the case of pci_channel_io_frozen */
> +	if (adev->cached_state != pci_channel_io_frozen)
> +		return;
> +
>   	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
>   		struct amdgpu_ring *ring = adev->rings[i];
>   

^ permalink raw reply	[flat|nested] 3+ messages in thread

* RE: [PATCH] drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume
  2021-10-04 16:04 ` Andrey Grodzovsky
@ 2021-10-05 11:43   ` Chen, Guchun
  0 siblings, 0 replies; 3+ messages in thread
From: Chen, Guchun @ 2021-10-05 11:43 UTC (permalink / raw)
  To: Grodzovsky, Andrey, amd-gfx, Koenig, Christian, Pan, Xinhui,
	Deucher, Alexander, Liu, Monk

[Public]

Thanks Andrey, I will update the name to be " pci_channel_state " when submitting.

Regards,
Guchun

-----Original Message-----
From: Grodzovsky, Andrey <Andrey.Grodzovsky@amd.com> 
Sent: Tuesday, October 5, 2021 12:04 AM
To: Chen, Guchun <Guchun.Chen@amd.com>; amd-gfx@lists.freedesktop.org; Koenig, Christian <Christian.Koenig@amd.com>; Pan, Xinhui <Xinhui.Pan@amd.com>; Deucher, Alexander <Alexander.Deucher@amd.com>; Liu, Monk <Monk.Liu@amd.com>
Subject: Re: [PATCH] drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume


On 2021-10-02 11:18 a.m., Guchun Chen wrote:
> In current code, when a PCI error state pci_channel_io_normal is 
> detectd, it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI 
> driver, and PCI driver will continue the execution of PCI resume 
> callback report_resume by pci_walk_bridge, and the callback will go 
> into amdgpu_pci_resume finally, where write lock is releasd 
> unconditionally without acquiring such lock first. In this case, a 
> deadlock will happen when other threads start to acquire the read lock.
>
> To fix this, add a member in amdgpu_device strucutre to cache 
> pci_channel_state, and only continue the execution in 
> amdgpu_pci_resume when it's pci_channel_io_frozen.
>
> Fixes: c9a6b82f45e2("drm/amdgpu: Implement DPC recovery")
> Suggested-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
> Signed-off-by: Guchun Chen <guchun.chen@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 ++++++
>   2 files changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index f4bceb2624fb..720d0ccecfe0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1094,6 +1094,7 @@ struct amdgpu_device {
>   
>   	bool                            no_hw_access;
>   	struct pci_saved_state          *pci_state;
> +	pci_channel_state_t		cached_state;


I would give a more descriptive name to this (e.g. pci_channel_state) Other then that Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>

Andrey


>   
>   	struct amdgpu_reset_control     *reset_cntl;
>   	uint32_t                        ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index bb5ad2b6ca13..1aaeb4b30edc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5368,6 +5368,8 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta
>   		return PCI_ERS_RESULT_DISCONNECT;
>   	}
>   
> +	adev->cached_state = state;
> +
>   	switch (state) {
>   	case pci_channel_io_normal:
>   		return PCI_ERS_RESULT_CAN_RECOVER; @@ -5510,6 +5512,10 @@ void 
> amdgpu_pci_resume(struct pci_dev *pdev)
>   
>   	DRM_INFO("PCI error: resume callback!!\n");
>   
> +	/* Only continue execution for the case of pci_channel_io_frozen */
> +	if (adev->cached_state != pci_channel_io_frozen)
> +		return;
> +
>   	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
>   		struct amdgpu_ring *ring = adev->rings[i];
>   

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-10-05 11:43 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-10-02 15:18 [PATCH] drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume Guchun Chen
2021-10-04 16:04 ` Andrey Grodzovsky
2021-10-05 11:43   ` Chen, Guchun

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