Dear Christian,
Am 16.03.22 um 11:08 schrieb Christian König:
Am 16.03.22 um 10:57 schrieb Paul Menzel:
Am 16.03.22 um 10:41 schrieb Christian König:
Am 16.03.22 um 07:21 schrieb Lang Yu:
On 03/16/ , Paul Menzel wrote:
Am 16.03.22 um 02:27 schrieb Lang Yu:
On 03/15/ , Paul Menzel wrote:
Am 14.03.22 um 03:45 schrieb Lang Yu:
Thank you for your patch. A shorter commit message summary would be:
drm/amdgpu: Work around VNC TMZ issue on CHIP_RAVEN
It is a hardware issue that VCN can't handle a GTT
backing stored TMZ buffer on CHIP_RAVEN series ASIC.
Where is that documented, and how can this be reproduced?
It is documented in AMD internal Confluence and JIRA.
Secure playback with a low VRAM config(thus TMZ buffer
will be allocted in GTT domain) may reproduce this issue.
It’d be great if as much of the details from this non-publicly accessible
information could be added to the commit message, and a way to reproduce
this as there does not seem to be a test for this. (Also I guess a tag with
a reference to the internal issue would be acceptable, so in case more
question surface in the future.)
Thanks. I will add an internal link.
Lang, please don't!
This isn't an information which is expected to be made public.
Well, how are then even the AMD folks able to link a (upstream) commit
to an issue?
Well quite simply: We don't do that since it isn't necessary.
What other ways do you (or future AMD developers) have then? (I would
also use *helpful* or *useful*.)
(In two years, when maybe nobody of the current AMD developers work at
AMD anymore, and a user bisects a problems to this patch I could imagine
it would help the future AMD developers to have this connection.)
If it’s not possible, even more detailed information about the issue
including how to reproduce it needs to be part of the commit message.
No, why should we do that? It's an AMD internal hardware problem which
we add a software workaround for here. The hardware details why and what
are completely irrelevant to the public.
All that we need to document is that VCN can't handle GTT on Raven, and
that's exactly what the commit message is doing. That's perfectly enough
to write a test case.
Thank you for clarifying, but I am not interested in the hardware
details, but how to reproduce and test the issue. And according to Lang
this information is present in the issue. Seeing how complex the
graphics driver are, a lot of documentation is not publicly available, a
recipe to manually reproduce and test the issue is most helpful.
Kind regards,
Paul
