Dear Dennis,


Thank you for you patch.

On 2020-07-08 09:48, Dennis Li wrote:
> During GPU reset, driver should hold on all external access to
> GPU, otherwise psp will randomly fail to do post, and then cause
> system hang.

Maybe update the commit message summary to read:

> Avoid external GPU access on GPU reset to fix system hang

As I am also experiencing system hangs, it would be great to have more
details. What systems are affected? What PSP firmware version? Will the
PSP firmware be fixed, or is the Linux driver violating the API.

How can the hang be reproduced?

Lastly, please explain your changes? Why does `atomic_read()` help for
example?

> v2:
> 1. add rwlock for some ioctls, debugfs and file-close function.
> 2. change to use dqm->is_resetting and dqm_lock for protection in kfd
> driver.
> 3. remove try_lock and change adev->in_gpu_reset as atomic, to avoid
> re-enter GPU recovery for the same GPU hang.
> 
> Signed-off-by: Dennis Li <Dennis.Li@amd.com>
> Change-Id: I7f77a72795462587ed7d5f51fe53a594a0f1f708

[…]


Kind regards,

Paul