RE: [PATCH] drm/amdgpu: added synchronization for psp cmd buf access

[Chen, Guchun]

[Public]

Thanks John. As in the same context, it's meaningless that two mutex target 
almost the same thing.

Regards,
Guchun

From: Clements, John <john.cleme...@amd.com>
Sent: Wednesday, August 4, 2021 11:34 AM
To: Chen, Guchun <guchun.c...@amd.com>; amd-gfx@lists.freedesktop.org
Cc: Zhang, Hawking <hawking.zh...@amd.com>; Li, Candice <candice...@amd.com>; 
Lazar, Lijo <lijo.la...@amd.com>
Subject: RE: [PATCH] drm/amdgpu: added synchronization for psp cmd buf access


[Public]

@Chen, Guchun<mailto:guchun.c...@amd.com>,
Based off your feedback I double checked the code, and I changed my opinion 
about it, I think it's better just to reuse the original mutex for now. I've 
submitted an updated patch for review

From: Clements, John <john.cleme...@amd.com<mailto:john.cleme...@amd.com>>
Sent: Tuesday, August 3, 2021 10:07 PM
To: Chen, Guchun <guchun.c...@amd.com<mailto:guchun.c...@amd.com>>; 
amd-gfx@lists.freedesktop.org<mailto:amd-gfx@lists.freedesktop.org>
Cc: Zhang, Hawking <hawking.zh...@amd.com<mailto:hawking.zh...@amd.com>>; Li, 
Candice <candice...@amd.com<mailto:candice...@amd.com>>; Lazar, Lijo 
<lijo.la...@amd.com<mailto:lijo.la...@amd.com>>
Subject: Re: [PATCH] drm/amdgpu: added synchronization for psp cmd buf access

Hello Guchun,

In most of those cases you are right it is redundant, the reason i kept them 
separate for now is to resolve this bug while also keeping those interfaces 
modular, and not affecting the psp submit sequence yet. We are planning a 
bigger change to that source to remove alot of the duplicate code regarding the 
cmd buffer prepare/submit flow and will probably go back down to one mutex 
there.

Thank you,
John Clements

________________________________
From: Chen, Guchun <guchun.c...@amd.com<mailto:guchun.c...@amd.com>>
Sent: Tuesday, August 3, 2021 9:58 PM
To: Clements, John <john.cleme...@amd.com<mailto:john.cleme...@amd.com>>; 
amd-gfx@lists.freedesktop.org<mailto:amd-gfx@lists.freedesktop.org> 
<amd-gfx@lists.freedesktop.org<mailto:amd-gfx@lists.freedesktop.org>>
Cc: Zhang, Hawking <hawking.zh...@amd.com<mailto:hawking.zh...@amd.com>>; Li, 
Candice <candice...@amd.com<mailto:candice...@amd.com>>; Lazar, Lijo 
<lijo.la...@amd.com<mailto:lijo.la...@amd.com>>
Subject: RE: [PATCH] drm/amdgpu: added synchronization for psp cmd buf access


[Public]



Before calling into psp_cmd_submit_buf, a mutex psp->cmd_buf_mutex is there, 
and after entering psp_cmd_submit_buf, there is another mutex psp->mutex, is it 
a bit redundant?



Regards,

Guchun



From: Clements, John <john.cleme...@amd.com<mailto:john.cleme...@amd.com>>
Sent: Tuesday, August 3, 2021 5:50 PM
To: amd-gfx@lists.freedesktop.org<mailto:amd-gfx@lists.freedesktop.org>
Cc: Zhang, Hawking <hawking.zh...@amd.com<mailto:hawking.zh...@amd.com>>; Li, 
Candice <candice...@amd.com<mailto:candice...@amd.com>>; Lazar, Lijo 
<lijo.la...@amd.com<mailto:lijo.la...@amd.com>>; Chen, Guchun 
<guchun.c...@amd.com<mailto:guchun.c...@amd.com>>
Subject: [PATCH] drm/amdgpu: added synchronization for psp cmd buf access



[AMD Official Use Only]



Submitting patch to synchronize access to psp cmd submission memory to resolve 
potential race conditions.