@AceLan Kao I think I found the i915 patch, which would fix this bug (along with a lot of other documented i915 fixes):
from (http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.39-rc1) commit 36d527deadf7d0c302e3452dde39465e74a65a08 Author: Chris Wilson <ch...@chris-wilson.co.uk> Date: Sat Mar 19 22:26:49 2011 +0000 drm/i915: Restore missing command flush before interrupt on BLT ring We always skipped flushing the BLT ring if the request flush did not include the RENDER domain. However, this neglects that we try to flush the COMMAND domain after every batch and before the breadcrumb interrupt (to make sure the batch is indeed completed prior to the interrupt firing and so insuring CPU coherency). As a result of the missing flush, incoherency did indeed creep in, most notable when using lots of command buffers and so potentially rewritting an active command buffer (i.e. the GPU was still executing from it even though the following interrupt had already fired and the request/buffer retired). As all ring->flush routines now have the same preconditions, de-duplicate and move those checks up into i915_gem_flush_ring(). Fixes gem_linear_blit. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35284 Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch> Tested-by: mengmeng.m...@intel.com ** Bug watch added: freedesktop.org Bugzilla #35284 http://bugs.freedesktop.org/show_bug.cgi?id=35284 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/761065 Title: [Sandybridge] Spurious "*ERROR* Hangcheck timer elapsed... blt ring idle" messages in dmesg when using compiz -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs