Created attachment 98888 [details]
dmesg

==System Environment==
--------------------------
Regression: Yes. But I unable to find good commit on both kernel and igt.

Non-working platforms: ILK

==kernel==
--------------------------
-nightly: ed60c2747e0be176f28dc3dadba564949d90d821 (fails)
-queued: 1cf0ba14740d96fbf6f58a201f000a34b74f4725 (fails)
    Author: Chris Wilson <chris@chris-wilson.co.uk>
    Date:   Mon May 5 09:07:33 2014 +0100

    drm/i915: Flush request queue when waiting for ring space

    During the review of

    commit 1f70999f9052f5a1b0ce1a55aff3808f2ec9fe42
    Author: Chris Wilson <chris@chris-wilson.co.uk>
    Date:   Mon Jan 27 22:43:07 2014 +0000

        drm/i915: Prevent recursion by retiring requests when the ring is full

    Ville raised the point that our interaction with request->tail was
    likely to foul up other uses elsewhere (such as hang check comparing
    ACTHD against requests).

    However, we also need to restore the implicit retire requests that certain
    test cases depend upon (e.g. igt/gem_exec_lut_handle), this raises the
    spectre that the ppgtt will randomly call i915_gpu_idle() and recurse
    back into intel_ring_begin().

    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78023
    Reviewed-by: Brad Volkin <bradley.d.volkin@intel.com>
    [danvet: Remove now unused 'tail' variable as spotted by Brad.]
    Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
-fixes: 05adaf1f101f25f40f12c29403e6488f0e45f6b6 (fails)
    Author: Jani Nikula <jani.nikula@intel.com>
    Date:   Fri May 9 14:52:34 2014 +0300

    drm/i915/vlv: reset VLV media force wake request register

    Media force wake get hangs the machine when the system is booted without
    displays attached. The assumption is that (at least some versions of)
    the firmware has skipped some initialization in that case.

    Empirical evidence suggests we need to reset the media force wake
    request register in addition to the render one to avoid hangs.

    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75895
    Reported-by: Imre Deak <imre.deak@intel.com>
    Reported-by: Darren Hart <dvhart@linux.intel.com>
    Tested-by: Darren Hart <dvhart@linux.intel.com>
    Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: Jani Nikula <jani.nikula@intel.com>

==Bug detailed description==
-----------------------------
igt/gem_ringfill/blitter fails

Output:
./gem_ringfill --run-subtest blitter
IGT-Version: 1.6-g8741c22 (x86_64) (Linux: 3.15.0-rc3_drm-intel-nightly_ed60c2_20140512+ x86_64)
filling blt ring: 100%
verifying
Subtest blitter: SUCCESS
Test requirement not met in function __real_main203, file gem_ringfill.c:223:
Last errno: 0, Success
Test requirement: (!(copy))

==Reproduce steps==
---------------------------- 
1. ./gem_ringfill --run-subtest blitter