- Again move the information relevant for driver writers next to the
  callbacks.
- Put the overview and userspace interface documentation into a DOC:
  section within the code.
- Remove the text that mmap needs to be coherent - since the
  DMA_BUF_IOCTL_SYNC landed that's no longer the case. But keep the text
  that for pte zapping exporters need to adjust the address space.
- Add a FIXME that kmap and the new begin/end stuff used by the SYNC
  ioctl don't really mix correctly. That's something I just realized
  while doing this doc rework.
- Augment function and structure docs like usual.

Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
  [sumits: fix cosmetic issues]
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-5-daniel.vetter@ffwll.ch

- Put the initial overview for dma-buf into dma-buf.rst.
- Put all the comments about detailed semantics into the right
  kernel-doc comment for functions or ops structure member.
- To allow that detail, switch the reworked kerneldoc to inline style
  for dma_buf_ops.
- Tie everything together into a much more streamlined overview
  comment, relying on the hyperlinks for all the details.
- Also sprinkle some links into the kerneldoc for dma_buf and
  dma_buf_attachment to tie it all together.

Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-4-daniel.vetter@ffwll.ch

This was missed when adding a dma_fence_get call. While at it also
remove the kerneldoc for the static inline helper - no point
documenting internals down to every detail.

Fixes: 30cd85dd ("dma-buf/sync_file: hold reference to fence when creating sync_file")
Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-3-daniel.vetter@ffwll.ch

Backmerge the docs-next branch from Jon into drm-misc so that we can
apply the dma-buf documentation cleanup patches. Git found a conflict
where there was none because both drm-misc and docs had identical
patches to clean up file rename issues in the rst include directives.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

It's deprecated and only should be used by drivers which still use
drm_platform_init, not by anyone else.

And indeed it's entirely unused and can be nuked.

This required a bit more fudging, but I guess kirin_dc_ops really
wants to operate on the platform_device, not something else. Also
bonus points for implementing abstraction, and then storing the vfunc
in a global variable.

v2: Don't break the build soooo badly :(
Note that the cleanup function is a bit confused: ade_data was never
set as drvdata, and calling drm_crtc_cleanup directly is a bug - this
is called indirectly through drm_mode_config_cleanup, which calls into
crtc->destroy, which already has the call to drm_crtc_cleanup. Which
means we can just nuke it.

Note this is the 2nd attempt after the first one failed and had to be
reverted again in

commit 9cd2e854
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Aug 17 13:59:40 2016 +0200

    Revert "drm/hisilicon: Don't set drm_device->platformdev"

Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209141944.22121-1-daniel.vetter@ffwll.ch

With the last round of changes all ioctls called by modern drivers now
have their own locking. Everything else is only allowed for legacy
drivers and hence the lack of locking doesn't matter.

One exception is nouveau, due to the DRIVER_KMS_LEGACY_CONTEXT flag.
But that only works its magic on the context and bufs ioctls. And
drm_bufs.c is protected with dev->struct_mutex, and drm_context.c by
the same and dev->ctxlist_mutex. That should be all safe, and we can
finally mandata drm-bkl-less ioctls for everyone!
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161210215255.7765-3-daniel.vetter@ffwll.ch

It only updates per-file feature flags. And all the ioctl which change
behaviour depending upon these flags (they're all kms features) do
_not_ hold the BKL. Therefor this is pure cargo-cult and can be
removed.

Note that there's a risk that the ioctl will behave inconsistently
when userspace is racing with itself, but that's ok. The only thing
it's not allowed to do is oops the kernel, and from an audit all
places are safe.

v2: Clarify that the inconsistency is only when userspace races
(Chris).
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161210215255.7765-2-daniel.vetter@ffwll.ch

No one looks at the major/minor versions except the unique/busid
stuff. If we protect that with the master_mutex (since it also affects
the unique of each master, oh well) we can mark these two IOCTL with
DRM_UNLOCKED.

While doing this I realized that the comment for the magic_map is
outdated, I've forgotten to update it in:

commit d2b34ee6
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jun 17 09:33:21 2016 +0200

    drm: Protect authmagic with master_mutex

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161210215255.7765-1-daniel.vetter@ffwll.ch

Not setting the fb modifiers flag is something different from setting
the fb modifiers to 0 (which means explicitly linear). We kinda failed
to document that properly. Spotted by Kristian.

Cc: hoegsberg@google.com
Reviewed-by: NKristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1478694996-4200-1-git-send-email-daniel.vetter@ffwll.ch

Looping twice when we can do it once is silly. Also use a consistent
style. Note that there's a good race with the connector list walking,
since that is no longer protected by mode_config.mutex. But that's for
a later patch to fix.

v2: Actually try to not blow up, somehow I lost the hunk that checks
we don't copy too much. Noticed by Chris.

v3:
- squash all drm_mode_getresources cleanups into one
- use consistent style for walking objects (Chris)

v4:
- Use u64_to_user_ptr (Chris)
- Don't forget to copy the last connector (Chris)

v5: Chris was right ...

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161211192019.29603-1-daniel.vetter@ffwll.ch

Joonas complained that writing ww_mutex_lock(&resv->lock, ctx) was too
intrusive compared to reservation_object_lock(resv, ctx);
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161115154642.31850-1-chris@chris-wilson.co.uk

Just prep work to polish and consolidate all the dma-buf related
documenation.

Unfortunately I didn't discover a way to both integrate this new file
into the overall toc while keeping it at the current place. Work
around that by moving it into the overall driver-api/index.rst.

Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

When DPMS was introduced to atomic, vblanks only worked when the crtc
was enabled and active. wait_for_vblanks were not converted to check for
crtc_state->active, which may cause an attempt for vblank_get to fail.

This is probably harmless, but convert from enable to active anyway.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1481204729-9058-2-git-send-email-maarten.lankhorst@linux.intel.com

It's supported now! Spotted while reviewing Chris' patch to add a
release hook.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161208102847.3063-1-daniel.vetter@ffwll.ch

Currently the reference for the dmabuf->obj is incremented for the
dmabuf in drm_gem_prime_handle_to_fd() (at the high level userspace
interface), but is released in drm_gem_dmabuf_release() (the lowlevel
handler). Improve the symmetry of the dmabuf->obj ownership by acquiring
the reference in drm_gem_dmabuf_export(). This makes it easier to use
the prime functions directly.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Update kerneldoc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161207214527.22533-1-chris@chris-wilson.co.uk

vgem (and our igt tests using vgem) need this. I suspect etnaviv will
fare similarly.

v2. Make it build. Oops.

Fixes: d5264ed3 ("drm: Return -ENOTSUPP when called for KMS cap with a non-KMS driver")
Cc: Michel Dänzer <michel.daenzer@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161207144939.22756-1-daniel.vetter@ffwll.ch

Instead of dealing with crtc details inside drm_atomic.c we should
just export a function that creates a new crtc fence for us and
use that.
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1481046437-18778-1-git-send-email-gustavo@padovan.org

We will ignored PSR setting if panel not support it. So, in this case,
we should return from analogix_dp_enable/disable_psr() without any
error code. Let's retrun 0 instead of -EINVAL when panel not support PSR
in analogix_dp_enable/disable_psr().
Signed-off-by: Nzain wang <wzz@rock-chips.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1481072253-8917-1-git-send-email-wzz@rock-chips.com

We now support nonblocking commits on drm_atomic_helper_commit()
so the comment is not valid anymore.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1480946626-30917-1-git-send-email-gustavo@padovan.org

Em Mon, 5 Dec 2016 14:23:01 -0700
Jonathan Corbet <corbet@lwn.net> escreveu:

> On Mon,  5 Dec 2016 09:41:40 -0200
> Mauro Carvalho Chehab <mchehab@s-opensource.com> wrote:
>
> > So, in order to check it, I wrote a small script that compares the files
> > and directories at Documentation/ with the ones at 00-INDEX.
> >
> > Then, I synchronized the entries, making the script happy.
> >
> > We might think on integrating the script with checkpatch.pl, but, as
> > we should get rid of 00-INDEX, it probably not worth the efforts.
>
> I would agree with that; I don't see the point of keeping those files
> around in the longer term.
>
> I've applied the set.  I do have a few quibbles with the final patch that
> I'll send separately, but they're not something to hold this set up for.

Jon,

Did a patch fixing the quibbles.

As it seems you didn't push yet the changeset upstream, feel free to
just fold it with patch 5/5 if you prefer so, or to add as a separate
patch at the end of the series.

Patch enclosed.

Thanks,
Mauro

[PATCH] docs: 00-INDEX: change text related to the building system

Let be clearer on those files related to the build system.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

If we cannot acquire the mode_config.mutex immediately, just back off and
queue a new attempt after the poll interval. This is mostly to stop the
hung task spam when the system is deadlocked, but it will also lessen
the load (in such extreme cases).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NEric Engestrom <eric.engestrom@imgtec.com>
[danvet:s/lock/mutex/ per Eric's comment.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161206113715.30382-1-chris@chris-wilson.co.uk

This is an attempt to make the previous fix a bit more robust going
forward.

v2:
* Only allow DRM_CAP_TIMESTAMP_MONOTONIC with UMS drivers (Daniel
  Vetter, Alex Deucher)
* Different logic to keep DRM_CAP_TIMESTAMP_MONOTONIC separate from
  the other caps (Daniel Vetter)
Signed-off-by: NMichel Dänzer <michel.daenzer@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161201073731.5716-1-michel@daenzer.net

Backmerge v4.9-rc8 to get at

commit e94bd173
Author: Michel Dänzer <michel.daenzer@amd.com>
Date:   Wed Nov 30 17:30:01 2016 +0900

drm: Don't call drm_for_each_crtc with a non-KMS driver

so I can apply Michel's follow-up patch.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since commit 8a357d10 ("drm: Nerf DRM_CONTROL nodes"), a
struct drm_device's ->control member is always NULL.

In the case of CONFIG_DEBUG_FS=y, amdgpu_debugfs_add_files() accesses
->control->debugfs_root though. This results in a NULL pointer
dereference.

Fix this by omitting the drm_debugfs_create_files() call for the
control minor debugfs directory which is now non-existent anyway.

Fixes: 8a357d10 ("drm: Nerf DRM_CONTROL nodes")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98915Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Tested-by: NMike Lothian <mike@fireburn.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161205203022.11671-1-nicstange@gmail.com

The drm_atomic_helper_connector_dpms
will set the connector back the old DPMS state
before returning. This makes it impossible to change
DPMS state of the connector.

Fixes: 0853695c
v2: edit of commit message
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Eric Engestrom <eric.engestrom@imgtec.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: dri-devel@lists.freedesktop.org
Cc: <drm-intel-fixes@lists.freedesktop.org>
Signed-off-by: NMarta Lofstedt <marta.lofstedt@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161205120408.13056-1-marta.lofstedt@intel.com

Merge branch 'exynos-drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-next

Just refactoring HDMI driver by using infoframe helper
function, fixing GSC Kconfig dependency issue and including trivial
cleanups.

* 'exynos-drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos: Use VIDEO_SAMSUNG_EXYNOS_GSC=n as GSC Kconfig dependency
  drm/exynos: gsc: fix spelling mistakes
  exynos-drm: Fix error messages to print flags and size
  drm/exynos/hdmi: refactor infoframe code

- lots of code cleanup
- lots of bug fixes
- expose rpm based fan info via hwmon
- lots of clock and powergating fixes
- SI register header cleanup and conversion to common format used by newer asics

* 'drm-next-4.10' of git://people.freedesktop.org/~agd5f/linux: (54 commits)
  drm/amdgpu: drop is_display_hung from display funcs
  drm/amdgpu/uvd: reduce IB parsing overhead on UVD5+ (v2)
  drm/amdgpu/uvd: consolidate code for fetching addr from ctx
  drm/amdgpu: Disable DPM in virtualization
  drm/amdgpu: use AMDGPU_GEM_CREATE_VRAM_CLEARED for VM PD/PTs (v2)
  drm/amdgpu: improve AMDGPU_GEM_CREATE_VRAM_CLEARED handling (v2)
  drm/amdgpu: fix error handling in amdgpu_bo_create_restricted
  drm/amdgpu: fix amdgpu_fill_buffer (v2)
  drm/amdgpu: remove amdgpu_irq_get_delayed
  amdgpu: Wrap dev_err() calls on vm faults with printk_ratelimit()
  amdgpu: Use dev_err() over vanilla printk() in vm_decode_fault()
  drm/amd/amdgpu: port of DCE v6 to new headers (v3)
  drm/amdgpu: cleanup unused iterator members for sdma v2.4
  drm/amdgpu: cleanup unused iterator members for sdma v3
  drm/amdgpu:impl vgt_flush for VI(V5)
  drm/amdgpu: enable uvd mgcg for Fiji.
  drm/amdgpu: refine cz uvd clock gate logic.
  drm/amdgpu: change log level to KERN_INFO in ci_dpm.c
  drm/amdgpu: always un-gate UVD REGS path.
  drm/amdgpu/sdma: fix typo in packet setup
  ...

- fix dma-buf export path to return correct SG table
- trivially implement direct dma-buf mapping
- allow DRAW_INSTANCED commands in validator
- make the driver work on i.MX6SX, yielding a working 2D/3D stack
together with Mareks MXS DRM driver

* 'drm-etnaviv-next' of git://git.pengutronix.de/lst/linux:
  MAINTAINERS: add etnaviv mailinglist
  drm/etnaviv: move linear window on MC1.0 parts if necessary
  drm/etnaviv: don't invoke OOM killer from dump code
  drm/etnaviv: fix gem_prime_get_sg_table to return new SG table
  drm/etnaviv: Allow DRAW_INSTANCED commands
  drm/etnaviv: implement dma-buf mmap

- BIT_PERF_PTRS uses 32-bit pointers to its subtables, we were parsing
them as 16-bit, causing various issues on newer boards.
- Support for MXM on GM20x and up.
- More display-related fixes.

* 'linux-4.10' of git://github.com/skeggsb/linux:
  drm/nouveau/mxm: warn more loudly on unsupported DCB version
  drm/nouveau/mxm: handle DCB 4.1 modification
  drm/nouveau/bios/mxm: handle digital connector table 1.1
  drm/nouveau: Queue hpd_work on (runtime) resume
  drm/nouveau: Rename acpi_work to hpd_work
  drm/nouveau/kms/nv50: Fix atomic pageflip events.
  drm/nouveau/fb/ram/gp100-: fix memory detection where FBP_NUM != FBPA_NUM
  drm/nouveau/bios/volt: pointers are 32-bit
  drm/nouveau/bios/vmap: pointers are 32-bit
  drm/nouveau/bios/timing: pointers are 32-bit
  drm/nouveau/bios/therm: pointers are 32-bit
  drm/nouveau/bios/perf: pointers are 32-bit
  drm/nouveau/bios/iccsense: pointers are 32-bit
  drm/nouveau/bios/fan: pointers are 32-bit
  drm/nouveau/bios/cstep: pointers are 32-bit
  drm/nouveau/bios/boost: pointers are 32-bit

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Allows MXM DCB modification to be handled on GM20x and newer boards.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

I suspect the version bump is just to signify that the table now specifies
pad macro/links instead of SOR/sublinks.

For our usage of the table, just recognising the new version is enough.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

There are a number of files/directories that don't contain
any documentation. They're related to ReST file conversion.

As a matter of completeness, since Makefile is also documented
there, add an entry for those files too.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Several entries were moved to a directory; others got simply
removed. Get rid of those entries.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Several directories and individual files don't have entries at
00-INDEX. Add them, using, as reference, the initial text inside
the documentation file(s).
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Instead of having descriptions for individual files inside
the process/ and admin-guide/ documentation, consolidate them
into one entry per directory, just like other descriptions
inside 00-INDEX.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

It is easy to forget adding/removing entries at the
Documentation/00-INDEX file. In a matter of fact, even before
ReST conversion, people use to forget adding things here, as
there are lots of missing stuff out there.

Now that we're doing a hard work converting entries to ReST,
and while this hole file is not outdated, it is good to have
some tool that would help to verify that this file is kept
updated.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

scripts/ver_linux has been rewritten as an awk script; update
documentation to reflect this fact.
Signed-off-by: NKevin Peng <kkpengboy@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Document device links as introduced in v4.10 with commits:
    4bdb3550 ("driver core: Add a wrapper around
                   __device_release_driver()")
    9ed98953 ("driver core: Functional dependencies tracking
                   support")
    8c73b428 ("PM / sleep: Make async suspend/resume of devices use
                   device links")
    21d5c57b ("PM / runtime: Use device links")
    baa8809f ("PM / runtime: Optimize the use of device links")
Signed-off-by: NLukas Wunner <lukas@wunner.de>
[ jc: Moved from core-api to driver-api ]
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

In function qxl_release_alloc(), when kmalloc() returns a NULL pointer,
it returns value 0 and parameter *ret is uninitialized. 0 means no error
to the callers of qxl_release_alloc(). The callers keep going and will
try to reference the uninitialized variable. This patch fixes the bug,
returning "-ENOMEM" when kmalloc() fails.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188911Signed-off-by: NPan Bian <bianpan2016@163.com>
[seanpaul fixed up subject prefix]
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1480777902-7648-1-git-send-email-bianpan2016@163.com