AMD General

Thanks Hawking for your review. I will check if this issue can be resolved from 
the user-space tool side.



Regards,
Ce,Sun
________________________________
From: Zhang, Hawking <[email protected]>
Sent: Friday, August 7, 2026 4:20 PM
To: Sun, Ce(Overlord) <[email protected]>; [email protected] 
<[email protected]>
Cc: Chai, Thomas <[email protected]>; Zhou1, Tao <[email protected]>; Yang, 
Stanley <[email protected]>; Lazar, Lijo <[email protected]>
Subject: RE: [PATCH] drm/amdgpu: Prevent RAS injection with lost bus caused by 
DPC

AMD General

Would it make more sense to set the RAS query ready flag for the DPC event as 
well?

We should keep ras_query_ready as the single flag for all RAS sysfs and debugfs 
nodes. This would help simplify the implementation in the RAS block. If the 
device is not available, then ras_query_ready should be set to false.

Regards,
Hawking

-----Original Message-----
From: Sun, Ce(Overlord) <[email protected]>
Sent: Friday, August 7, 2026 3:03 PM
To: [email protected]
Cc: Zhang, Hawking <[email protected]>; Chai, Thomas <[email protected]>; 
Zhou1, Tao <[email protected]>; Yang, Stanley <[email protected]>; Lazar, 
Lijo <[email protected]>; Sun, Ce(Overlord) <[email protected]>
Subject: [PATCH] drm/amdgpu: Prevent RAS injection with lost bus caused by DPC

When DPC events occur, the GPU bus becomes unavailable and all user-space 
operations should be blocked. There is a timing race where rastool may still 
send RAS error injection commands to the driver after bus loss, which leads 
unexpected failures.

Extend the readiness check in ras debugfs write handler by adding
amdgpu_device_bus_status_check() to detect bus lost state. Print warning and 
reject injection requests to notify user-space the function is inaccessible.

Signed-off-by: Ce Sun <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
index 35eb87591740..4943be034c80 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -564,7 +564,7 @@ static ssize_t amdgpu_ras_debugfs_ctrl_write(struct file *f,
        struct ras_debug_if data;
        int ret = 0;

-       if (!amdgpu_ras_get_error_query_ready(adev)) {
+       if (!amdgpu_ras_get_error_query_ready(adev) ||
+amdgpu_device_bus_status_check(adev)) {
                dev_warn(adev->dev, "RAS WARN: error injection "
                                "currently inaccessible\n");
                return size;
--
2.34.1

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