Re: [Regression] [Radeon] Stream command failures and render problemsin Evergreen (Radeon HD 5600) in kernel 3.4

From: Jerome Glisse
Date: Thu Jun 07 2012 - 12:21:59 EST


On Thu, Jun 7, 2012 at 11:35 AM, Roland Dreier <roland@xxxxxxxxxxxxxxx> wrote:
>> Update your libdrm to libdrm from git should fix your issue.
>
> That's unfortunate -- it means a kernel change breaks working userspace?

Yes and no, welcome to GPU world. So this patch is suppose to report
some GPU informations to userspace, sadly on some GPU we report wrong
informations (that's a bug). So solution is to fix kernel to report
right information, i think the following patch does that.
http://www.mail-archive.com/stable@xxxxxxxxxxxxxxx/msg09247.html

The no side, is to have it broken you also need to have upgraded your
libdrm, ie old libdrm/radeon with this kernel will work as previously.
This issue have been fix recently in libdrm :
http://cgit.freedesktop.org/mesa/drm/commit/?id=c2b77a02d4e188cfa6d1b73a721946fd9b1d3577

Of course here i am assuming that the bug Brian is experiencing is
related to wrong tile infos reporting.

Cheers,
Jerome
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