https://bugs.freedesktop.org/show_bug.cgi?id=88561
Bug ID: 88561 Summary: [radeonsi][regression,bisected] Depth test/buffer issues in Portal Product: Mesa Version: git Hardware: Other OS: All Status: NEW Severity: normal Priority: medium Component: Drivers/Gallium/radeonsi Assignee: dri-devel@lists.freedesktop.org Reporter: daniel@constexpr.org
Created attachment 112428 --> https://bugs.freedesktop.org/attachment.cgi?id=112428&action=edit Bad frame
With current Mesa master (commit 461103ef64858e9d81073fad1bd8222b70b2754b), (some) background geometry will be randomly drawn above foreground for some frames in Portal (also observed in the Portal mod Rexaura). It does not happen often and the same scene may be fine depending on what was loaded before or just randomness.
Bisecting blames commit 02ba7334d35cf8182048c17a149b16f18104c6bf Author: Marek Olšák marek.olsak@amd.com Date: Sun Jan 4 22:16:53 2015 +0100
radeonsi: don't use TC L2 for updating descriptors on SI
It's causing problems, because we mix uncached CP DMA with cached WRITE_DATA when updating the same memory.
The solution for SI is to use uncached access here, because CP DMA doesn't support cached access.
CIK will be handled in the next patch.
Reviewed-by: Michel Dänzer michel.daenzer@amd.com
Simply reverting this commit on master causes other rendering issues.
GPU: Radeon HD 7950 (OpenGL renderer string: Gallium 0.4 on AMD TAHITI) LLVM compiled from svn last week (r225584) GCC: 4.8.4 Kernel: Linux 3.18.2-gentoo Distro: Gentoo