Commit Graph

22 Commits

Author SHA1 Message Date
Chris Wilson 3012ea60c5 drm/i915/selftests: Hold rpm for unparking
The call to i915_gem_unpark() checks that we hold a rpm wakeref before
taking a long term wakeref for i915->gt.awake. We should therefore make
sure we do hold the wakeref when directly calling unpark to disable
the retire worker.

Fixes: 932cac10c8 ("drm/i915/selftests: Prevent background reaping of active objects")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180809063449.4474-1-chris@chris-wilson.co.uk
(cherry picked from commit 7b5ee80a5d)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2018-08-15 13:41:08 -07:00
Chris Wilson cecb368d2f drm/i915/selftests: Filter out both physical address swizzles
In our swizzling selftests, we cannot predict the physical address of
the target page (at least not simply!) and so skip bit17 swizzles.
However, there are two bit17 swizzle modes and we only skipped one, with
the second being observed on the lab gdg causing the test to fail,
as soon as we hit a page with bit17 set in its address.

Testcase: igt/drv_selftest/live_objects #gdg
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180709194915.5789-1-chris@chris-wilson.co.uk
2018-07-10 09:53:41 +01:00
Chris Wilson 932cac10c8 drm/i915/selftests: Prevent background reaping of active objects
igt_mmap_offset_exhaustion() wants to test what happens when the mmap
space is filled with zombie objects, objects discarded by userspace but
still active on the GPU. As they are only protected by the active
reference, we have to be certain that active reference is kept while we
peek into our dangling pointer. That active reference should not be
freed until we retire, but we do that retirement from a background
thread. This leaves us with a subtle timing problem, exacerbated and
highlighted by KASAN:

<3>[  132.380399] BUG: KASAN: use-after-free in drm_gem_create_mmap_offset+0x8c/0xd0
<3>[  132.380430] Read of size 8 at addr ffff8801e13245f8 by task drv_selftest/5822

<4>[  132.380470] CPU: 0 PID: 5822 Comm: drv_selftest Tainted: G     U            4.18.0-rc3-g7ae7763aa2be-kasan_48+ #1
<4>[  132.380473] Hardware name: Dell Inc. XPS 8300  /0Y2MRG, BIOS A06 10/17/2011
<4>[  132.380475] Call Trace:
<4>[  132.380481]  dump_stack+0x7c/0xbb
<4>[  132.380487]  print_address_description+0x65/0x270
<4>[  132.380493]  kasan_report+0x25b/0x380
<4>[  132.380497]  ? drm_gem_create_mmap_offset+0x8c/0xd0
<4>[  132.380503]  drm_gem_create_mmap_offset+0x8c/0xd0
<4>[  132.380584]  i915_gem_object_create_mmap_offset+0x6d/0x100 [i915]
<4>[  132.380650]  igt_mmap_offset_exhaustion+0x462/0x940 [i915]
<4>[  132.380714]  ? i915_gem_close_object+0x740/0x740 [i915]
<4>[  132.380784]  ? igt_gem_huge+0x269/0x3d0 [i915]
<4>[  132.380865]  __i915_subtests+0x5a/0x160 [i915]
<4>[  132.380936]  __run_selftests+0x1a2/0x2f0 [i915]
<4>[  132.381008]  i915_live_selftests+0x4e/0x80 [i915]
<4>[  132.381071]  i915_pci_probe+0xd8/0x1b0 [i915]
<4>[  132.381077]  pci_device_probe+0x1c5/0x3a0
<4>[  132.381087]  driver_probe_device+0x6b6/0xcb0
<4>[  132.381094]  __driver_attach+0x22d/0x2c0
<4>[  132.381100]  ? driver_probe_device+0xcb0/0xcb0
<4>[  132.381103]  bus_for_each_dev+0x113/0x1a0
<4>[  132.381108]  ? check_flags.part.24+0x450/0x450
<4>[  132.381112]  ? subsys_dev_iter_exit+0x10/0x10
<4>[  132.381123]  bus_add_driver+0x38b/0x6e0
<4>[  132.381131]  driver_register+0x189/0x400
<4>[  132.381136]  ? 0xffffffffc12d8000
<4>[  132.381140]  do_one_initcall+0xa0/0x4c0
<4>[  132.381145]  ? initcall_blacklisted+0x180/0x180
<4>[  132.381152]  ? do_init_module+0x4a/0x54c
<4>[  132.381156]  ? rcu_lockdep_current_cpu_online+0xdc/0x130
<4>[  132.381161]  ? kasan_unpoison_shadow+0x30/0x40
<4>[  132.381169]  do_init_module+0x1b5/0x54c
<4>[  132.381177]  load_module+0x619e/0x9b70
<4>[  132.381202]  ? module_frob_arch_sections+0x20/0x20
<4>[  132.381211]  ? vfs_read+0x257/0x2f0
<4>[  132.381214]  ? vfs_read+0x257/0x2f0
<4>[  132.381221]  ? kernel_read+0x8b/0x130
<4>[  132.381231]  ? copy_strings_kernel+0x120/0x120
<4>[  132.381244]  ? __se_sys_finit_module+0x17c/0x1a0
<4>[  132.381248]  __se_sys_finit_module+0x17c/0x1a0
<4>[  132.381252]  ? __ia32_sys_init_module+0xa0/0xa0
<4>[  132.381261]  ? __se_sys_newstat+0x77/0xd0
<4>[  132.381265]  ? cp_new_stat+0x590/0x590
<4>[  132.381269]  ? kmem_cache_free+0x2f0/0x340
<4>[  132.381285]  do_syscall_64+0x97/0x400
<4>[  132.381292]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[  132.381295] RIP: 0033:0x7eff4af46839
<4>[  132.381297] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
<4>[  132.381426] RSP: 002b:00007ffcd84f4cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
<4>[  132.381432] RAX: ffffffffffffffda RBX: 000055dfdeb429a0 RCX: 00007eff4af46839
<4>[  132.381435] RDX: 0000000000000000 RSI: 000055dfdeb43670 RDI: 0000000000000004
<4>[  132.381437] RBP: 000055dfdeb43670 R08: 0000000000000004 R09: 0000000000000000
<4>[  132.381440] R10: 00007ffcd84f4e60 R11: 0000000000000246 R12: 0000000000000000
<4>[  132.381442] R13: 000055dfdeb3bec0 R14: 0000000000000000 R15: 000000000000003b

<3>[  132.381466] Allocated by task 5822:
<4>[  132.381485]  kmem_cache_alloc+0xdf/0x2e0
<4>[  132.381546]  i915_gem_object_create_internal+0x24/0x1e0 [i915]
<4>[  132.381609]  igt_mmap_offset_exhaustion+0x257/0x940 [i915]
<4>[  132.381677]  __i915_subtests+0x5a/0x160 [i915]
<4>[  132.381742]  __run_selftests+0x1a2/0x2f0 [i915]
<4>[  132.381806]  i915_live_selftests+0x4e/0x80 [i915]
<4>[  132.381865]  i915_pci_probe+0xd8/0x1b0 [i915]
<4>[  132.381868]  pci_device_probe+0x1c5/0x3a0
<4>[  132.381871]  driver_probe_device+0x6b6/0xcb0
<4>[  132.381874]  __driver_attach+0x22d/0x2c0
<4>[  132.381877]  bus_for_each_dev+0x113/0x1a0
<4>[  132.381880]  bus_add_driver+0x38b/0x6e0
<4>[  132.381884]  driver_register+0x189/0x400
<4>[  132.381886]  do_one_initcall+0xa0/0x4c0
<4>[  132.381889]  do_init_module+0x1b5/0x54c
<4>[  132.381892]  load_module+0x619e/0x9b70
<4>[  132.381895]  __se_sys_finit_module+0x17c/0x1a0
<4>[  132.381898]  do_syscall_64+0x97/0x400
<4>[  132.381901]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

<3>[  132.381914] Freed by task 150:
<4>[  132.381931]  kmem_cache_free+0xb7/0x340
<4>[  132.381995]  __i915_gem_free_objects+0x875/0xf50 [i915]
<4>[  132.382054]  __i915_gem_free_work+0x69/0xb0 [i915]
<4>[  132.382058]  process_one_work+0x78b/0x1740
<4>[  132.382061]  worker_thread+0x82/0xb80
<4>[  132.382064]  kthread+0x30c/0x3d0
<4>[  132.382067]  ret_from_fork+0x3a/0x50

<3>[  132.382081] The buggy address belongs to the object at ffff8801e1324500
                   which belongs to the cache drm_i915_gem_object of size 1168
<3>[  132.382133] The buggy address is located 248 bytes inside of
                   1168-byte region [ffff8801e1324500, ffff8801e1324990)
<3>[  132.382179] The buggy address belongs to the page:
<0>[  132.382202] page:ffffea000784c800 count:1 mapcount:0 mapping:ffff8801dedf6500 index:0xffff8801e1323ec0 compound_mapcount: 0
<0>[  132.382251] flags: 0x8000000000008100(slab|head)
<1>[  132.382274] raw: 8000000000008100 ffff8801d6317440 ffff8801d6317440 ffff8801dedf6500
<1>[  132.382307] raw: ffff8801e1323ec0 0000000000140013 00000001ffffffff 0000000000000000
<1>[  132.382339] page dumped because: kasan: bad access detected

<3>[  132.382373] Memory state around the buggy address:
<3>[  132.382395]  ffff8801e1324480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
<3>[  132.382426]  ffff8801e1324500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
<3>[  132.382457] >ffff8801e1324580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
<3>[  132.382488]                                                                 ^
<3>[  132.382517]  ffff8801e1324600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
<3>[  132.382548]  ffff8801e1324680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

This patch tricks the system into running without the background retire
thread, until after we finish the test. The only reaping should then be
performed by the mmap offset routine to reclaim the space as required.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180709130208.11730-1-chris@chris-wilson.co.uk
2018-07-09 15:09:51 +01:00
Chris Wilson e147913247 drm/i915/selftests: Magic numbers for old Y-tiling
i915g has a slightly different tiling layout, and so requires a
different reference swizzle pattern.

Testcase: igt/drv_selftests/live_objects #gdg
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180707100405.817-1-chris@chris-wilson.co.uk
2018-07-09 11:02:36 +01:00
Chris Wilson a523697857 drm/i915: Start returning an error from i915_vma_move_to_active()
Handling such a late error in request construction is tricky, but to
accommodate future patches which may allocate here, we potentially could
err. To handle the error after already adjusting global state to track
the new request, we must finish and submit the request. But we don't
want to use the request as not everything is being tracked by it, so we
opt to cancel the commands inside the request.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706103947.15919-3-chris@chris-wilson.co.uk
2018-07-06 18:22:37 +01:00
Chris Wilson da99fe5f85 drm/i915: Refactor export_fence() after i915_vma_move_to_active()
Currently all callers are responsible for adding the vma to the active
timeline and then exporting its fence. Combine the two operations into
i915_vma_move_to_active() to move all the extra handling from the
callers to the single site.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706103947.15919-1-chris@chris-wilson.co.uk
2018-07-06 18:22:34 +01:00
Chris Wilson e16f4c36cb drm/i915/selftests: Skip making an object busy if the GPU is wedged
If the GPU is wedged, we cannot make the object busy as trying to
submit a request will generate -EIO. Skip to the end of the test.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706065332.15214-4-chris@chris-wilson.co.uk
2018-07-06 11:24:31 +01:00
Chris Wilson e5d2435bfa drm/i915/selftests: Destroy partial tiling vma after use
As we keep VMA around until the object is destroyed, when testing
partial tiling we instantiate many, many VMA (as the object is huge
allowing for many different partial regions). We test elsewhere our
handling of populating large objects with a full set of VMA and checking
we can retrieve them afterwards, but in this test we incur the cost of
flushing all VMA after every GTT write, dramatically slowing down the
test.

References: https://bugs.freedesktop.org/show_bug.cgi?id=107130
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706065332.15214-2-chris@chris-wilson.co.uk
2018-07-06 11:24:00 +01:00
Chris Wilson 73d8e5fba5 drm/i915/selftests: Detect unknown swizzling correctly
i915_gem_detect_bit_6_swizzle() tries to hide unknown swizzling from
userspace (and ourselves) leaving us with the only clue inside
i915->quirks & QUIRK_PIN_SWIZZLED_PAGES. If we see this bit set, it
means that we really have no clue as to what the swizzle pattern is
being used in any one page and so cannot compute what the reference
value should be in our tiling selftests. We have to skip the test.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107133
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180705171523.18462-1-chris@chris-wilson.co.uk
2018-07-05 20:53:01 +01:00
Chris Wilson be01de596e drm/i915/selftests: Attach the fence to the object when making busy
make_obj_busy() makes a dummy busy object, but didn't attach the fence
to the reservation object, so it would not have registered as busy. For
completeness, attach the dummy request as the exclusive fence and mark
the object as written (in i915_vma_move_to_active)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180629133717.11761-2-chris@chris-wilson.co.uk
2018-06-29 21:07:39 +01:00
Thomas Zimmermann a24362ead9 drm/i915: Replace drm_dev_unref with drm_dev_put
This patch unifies the naming of DRM functions for reference counting
of struct drm_device. The resulting code is more aligned with the rest
of the Linux kernel interfaces.

Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180618110154.30462-6-tdz@users.sourceforge.net
2018-06-28 19:09:46 +02:00
Chris Wilson 82ad6443a5 drm/i915/gtt: Rename i915_hw_ppgtt base member
In the near future, I want to subclass gen6_hw_ppgtt as it contains a
few specialised members and I wish to add more. To avoid the ugliness of
using ppgtt->base.base, rename the i915_hw_ppgtt base member
(i915_address_space) as vm, which is our common shorthand for an
i915_address_space local.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180605153758.18422-1-chris@chris-wilson.co.uk
2018-06-05 21:11:20 +01:00
Chris Wilson e61e0f51ba drm/i915: Rename drm_i915_gem_request to i915_request
We want to de-emphasize the link between the request (dependency,
execution and fence tracking) from GEM and so rename the struct from
drm_i915_gem_request to i915_request. That is we may implement the GEM
user interface on top of requests, but they are an abstraction for
tracking execution rather than an implementation detail of GEM. (Since
they are not tied to HW, we keep the i915 prefix as opposed to intel.)

In short, the spatch:
@@

@@
- struct drm_i915_gem_request
+ struct i915_request

A corollary to contracting the type name, we also harmonise on using
'rq' shorthand for local variables where space if of the essence and
repetition makes 'request' unwieldy. For globals and struct members,
'request' is still much preferred for its clarity.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180221095636.6649-1-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2018-02-21 20:57:22 +00:00
Chris Wilson 015df4f54e drm/i915/selftests: Report setup errors for igt_partial_tiling
igt_partial_tiling managed to fail with an -EBUSY. This usually means a
pin leak, but that should be impossible given the test setup. Add a
couple of error messages to help identify the path that failed.

References: https://bugs.freedesktop.org/show_bug.cgi?id=105073
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180213120940.21579-1-chris@chris-wilson.co.uk
2018-02-13 12:40:28 +00:00
Chris Wilson 693b1ccabe drm/i915/selftests: Take rpm wakeref around partial tiling tests
Since the partial tiling tests are poking into the GGTT to watch the
fence registers in operation, it itself needs the device rpm wakeref in
order for the GGTT to remain accessible.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107115653.10716-1-chris@chris-wilson.co.uk
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
2017-11-07 17:50:34 +00:00
Chris Wilson b4563f595e drm/i915: Pin fence for iomap
Acquire the fence register for the iomap in i915_vma_pin_iomap() on
behalf of the caller.

We probably want for the caller to specify whether the fence should be
pinned for their usage, but at the moment all callers do want the
associated fence, or none, so take it on their behalf.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171009084401.29090-1-chris@chris-wilson.co.uk
2017-10-09 17:07:29 +01:00
Chris Wilson 10e9bd9ab0 drm/i915: Wake device for emitting request during selftest
igt_mmap_offset_exhaustion() selftest was using live requests to make an
object busy, but we did not hold a runtime pm wakeref for submitting the
requests. Acquire it to avoid triggering "RPM wakelock ref not held
during HW access" warnings.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170411234427.14841-3-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2017-04-12 13:38:06 +01:00
Chris Wilson ef74921bc6 drm/i915: Combine write_domain flushes to a single function
In the next patch, we will introduce a new cache domain for
differentiating between GTT access and direct WC access. This will
require us to include WC in our write_domain flushes. Rather than
duplicate a third function, combine the existing two into one and
flushing WC writes will then be automatically handled as well.

v2: Be smarter and clearer by passing in the write domains to flush (Joonas)
v3: One missed ~ in v2 conversion

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170412110111.26626-1-chris@chris-wilson.co.uk
2017-04-12 12:35:16 +01:00
Chris Wilson 3d81d589d6 drm/i915: Test exhaustion of the mmap space
An unlikely error condition that we can simulate by stealing most of
the range before trying to insert new objects.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-20-chris@chris-wilson.co.uk
2017-02-13 20:45:45 +00:00
Chris Wilson 48d8981720 drm/i915: Test partial mappings
Create partial mappings to cover a large object, investigating tiling
(fenced regions) and VMA reuse.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-19-chris@chris-wilson.co.uk
2017-02-13 20:45:44 +00:00
Chris Wilson 12d30d8793 drm/i915: Add a live seftest for GEM objects
Starting with a placeholder test just to reassure that we can create a
test object,

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-18-chris@chris-wilson.co.uk
2017-02-13 20:45:43 +00:00
Chris Wilson 8335fd65ce drm/i915: Add selftests for object allocation, phys
The phys object is a rarely used device (only very old machines require
a chunk of physically contiguous pages for a few hardware interactions).
As such, it is not exercised by CI and to combat that we want to add a
test that exercises the phys object on all platforms.

v2: Always set err on error paths and not rely on inheriting the err.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-17-chris@chris-wilson.co.uk
2017-02-13 20:45:42 +00:00