<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Intel GM45 graphics glitches with Kernel 3.18" href="https://bugs.freedesktop.org/show_bug.cgi?id=87279#c7">Comment # 7</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Intel GM45 graphics glitches with Kernel 3.18" href="https://bugs.freedesktop.org/show_bug.cgi?id=87279">bug 87279</a> from <a class="email" href="mailto:ugis.germanis@gmail.com" title="Ugis Germanis <ugis.germanis@gmail.com>"> Ugis Germanis</a> <pre>After long night of bisecting, I've found the commit that seem to fix this bug --------------------------------------------------------------------------- d472fcc8379c062bd56a3876fc6ef22258f14a91 is the first bad commit commit d472fcc8379c062bd56a3876fc6ef22258f14a91 Author: Daniel Vetter <<a href="mailto:daniel.vetter@ffwll.ch">daniel.vetter@ffwll.ch</a>> Date: Mon Nov 24 11:12:42 2014 +0100 drm/i915: Disallow pin ioctl completely for kms drivers The problem here is that SNA pins batchbuffers to etch out a bit more performance. Iirc it started out as a w/a for i830M (which we've implemented in the kernel since a long time already). The problem is that the pin ioctl wasn't added in commit d23db88c3ab233daed18709e3a24d6c95344117f Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> Date: Fri May 23 08:48:08 2014 +0200 drm/i915: Prevent negative relocation deltas from wrapping Fix this by simply disallowing pinning from userspace so that the kernel is in full control of batch placement again. Especially since distros are moving towards running X as non-root, so most users won't even be able to see any benefits. UMS support is dead now, but we need this minimal patch for backporting. Follow-up patch will remove the pin ioctl code completely. Note to backporters: You must have both commit b45305fce5bb1abec263fcff9d81ebecd6306ede Author: Daniel Vetter <<a href="mailto:daniel.vetter@ffwll.ch">daniel.vetter@ffwll.ch</a>> Date: Mon Dec 17 16:21:27 2012 +0100 drm/i915: Implement workaround for broken CS tlb on i830/845 which laned in 3.8 and commit c4d69da167fa967749aeb70bc0e94a457e5d00c1 Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> Date: Mon Sep 8 14:25:41 2014 +0100 drm/i915: Evict CS TLBs between batches which is also marked cc: stable. Otherwise this could introduce a regression by disabling the userspace w/a without the kernel w/a being fully functional on i830/45. References: <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [gm45] [drm:init_ring_common]: *ERROR* render ring initialization failed" href="show_bug.cgi?id=76554#c116">https://bugs.freedesktop.org/show_bug.cgi?id=76554#c116</a> Cc: <a href="mailto:stable@vger.kernel.org">stable@vger.kernel.org</a> # requires c4d69da167fa967749a and v3.8 Cc: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> Signed-off-by: Daniel Vetter <<a href="mailto:daniel.vetter@intel.com">daniel.vetter@intel.com</a>> :040000 040000 4345ff9fc3b775222a59890caf35c033b5a5bacf c8a157f364e4e0490b6bf1df0321a24bfd069f2e M drivers</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>