Replace drm_format_num_planes(fb->pixel_format) with just
fb->format->num_planes. Avoids the expensive format info lookup.

@@
struct drm_framebuffer *a;
struct drm_framebuffer b;
@@
(
- drm_format_num_planes(a->pixel_format)
+ a->format->num_planes
|
- drm_format_num_planes(b.pixel_format)
+ b.format->num_planes
)

@@
struct drm_plane_state *a;
struct drm_plane_state b;
@@
(
- drm_format_num_planes(a->fb->pixel_format)
+ a->fb->format->num_planes
|
- drm_format_num_planes(b.fb->pixel_format)
+ b.fb->format->num_planes
)

@@
struct drm_framebuffer *a;
identifier T;
@@
  T = a->pixel_format
<+...
- drm_format_num_planes(T)
+ a->format->num_planes
...+>

@@
struct drm_framebuffer b;
identifier T;
@@
  T = b.pixel_format
<+...
- drm_format_num_planes(T)
+ b.format->num_planes
...+>

v2: Rerun spatch due to code changes

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481751022-18015-1-git-send-email-ville.syrjala@linux.intel.com

Any framebuffer that doesn't have proper format information when
drm_framebuffer_init() is called is a bug. Let's warn and return
an error to avoid oopsing the kernel later due to dereferencing the
NULL fb->format pointer.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Suggested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-23-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>

Make sure the framebuffer format info is available as early as possible
for fbs we inherit from the BIOS. This will allow us to use the fb as
if it was fully formed before we register it.

Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-22-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To avoid having to look up the format information struct every time,
let's just store a pointer to it under drm_framebuffer.

v2: Don't populate the fb->format pointer in drm_framebuffer_init().
    instead we'll treat a NULL format as an error later

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-20-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>

Populating fb->dev before drm_framebuffer_init() allows us to use
fb->dev already while validating the framebuffer. Let's have
drm_helper_mode_fill_fb_struct() do that for us.

Also make drm_framebuffer_init() warn us if a different device
pointer is passed to it than was passed to
drm_helper_mode_fill_fb_struct().

v2: Reject fbs with invalid fb->dev (Laurent)

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com> (v1)
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-19-git-send-email-ville.syrjala@linux.intel.com

We want the fbs inherited from the BIOS to be more or less fully working
prior to actually registering them. This will allow us to just pass the
fb to various helper function instead of having to pass all the
different parameters separately.

Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-18-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want framebuffers to be mostly useable already before
drm_framebuffer_init() get called, and so we will start demanding that
all the interesting format/size/etc. information be filled in before
drm_framebuffer_init(). drm_helper_mode_fill_fb_struct() will do that
for us, so let's make sure it gets called before drm_framebuffer_init().

Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-17-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want framebuffers to be mostly useable already before
drm_framebuffer_init() is called, and so we will start demanding that
all the interesting format/size/etc. information be filled in before
drm_framebuffer_init(). drm_helper_mode_fill_fb_struct() will do that
for us, so let's make sure it gets called before drm_framebuffer_init().

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-16-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pass the drm_device to drm_helper_mode_fill_fb_struct() so that we can
populate fb->dev early. Will make it easier to use the fb before we
register it.

@@
identifier fb, mode_cmd;
@@
 void drm_helper_mode_fill_fb_struct(
+				     struct drm_device *dev,
				     struct drm_framebuffer *fb,
				     const struct drm_mode_fb_cmd2 *mode_cmd
				     );

@@
identifier fb, mode_cmd;
@@
 void drm_helper_mode_fill_fb_struct(
+				     struct drm_device *dev,
				     struct drm_framebuffer *fb,
				     const struct drm_mode_fb_cmd2 *mode_cmd
				     )
{ ... }

@@
function func;
identifier dev;
expression E1, E2;
@@
func(struct drm_device *dev, ...)
{
 ...
 drm_helper_mode_fill_fb_struct(
+				dev,
				E1, E2);
 ...
}

@@
expression E1, E2;
@@
 drm_helper_mode_fill_fb_struct(
+				dev,
				E1, E2);

v2: Rerun spatch due to code changes
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481748539-18283-1-git-send-email-ville.syrjala@linux.intel.com

It looks like the BOE panel FW didn't ack the DPCD600 signal from the
host device, this will cause the panel to hang on the startup display.

The root cause is that we use the fast link mode when we enter and
exit PSR, the issue is gone if we switch from the fast link to main
link mode.
Signed-off-by: NCaesar Wang <wxt@rock-chips.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1481338159-7189-1-git-send-email-wxt@rock-chips.com

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-12-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

So it looks like the code is trying to pick between the passed in fb and
crtc->primary->fb based on that funky 'bool atomic'. But later it will
mix uses of both drm_fb (which was picked by the aforementioned logic)
and crtc->primary->fb. So looks like a bug to me. Let's make it use
drm_fb only.

Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-11-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my ppor
coccinelle skills later.

In some places the local variable was already there, just not used
consistently.

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NBrian Starkey <brian.starkey@arm.com>
Acked-by: NLiviu Dudau <liviu.dudau@arm.com>

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my ppor
coccinelle skills later.

Cc: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-9-git-send-email-ville.syrjala@linux.intel.comAcked-by: NAlexey Brodkin <abrodkin@synopsys.com>

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-8-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-7-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-6-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use DIV_ROUND_UP() instead of hand rolling it. Just a drive-by change.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-4-git-send-email-ville.syrjala@linux.intel.com

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-3-git-send-email-ville.syrjala@linux.intel.com

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

While at it switch over to using the pixel format rather than
depth+bpp.

Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

THS8135 is a configurable video DAC, but no configuration is actually
necessary to make it work.

For now use the dumb-vga-dac driver to support it.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1481623759-12786-4-git-send-email-bgolaszewski@baylibre.com

THS8135 is a configurable video DAC. Add DT bindings for this chip.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1481623759-12786-3-git-send-email-bgolaszewski@baylibre.com

fsl is already fully demidlayered in the probe function, but for
convenience stuck with drm_put_dev. Call the unregister/unref parts
separately, to make sure this driver works correct.

v2: Rebase.

Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Stefan Agner <stefan@agner.ch>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213175449.24525-1-daniel.vetter@ffwll.ch

We should be checking for IS_ERR() instead of NULL because
drm_dev_alloc() returns error pointers.

Fixes: 45d59d70 ("drm: Add new driver for MXSFB controller")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213122332.GA7519@elgon.mountain

Main pull request for drm for 4.10 kernel - resync drm-misc with full
4.10 state (2 new drivers) so that we can start pulling in all the
refactorings for 4.11!
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

If atomic state is available, use this to read the current plane in
GetCrtc/GetPlane, rather than the legacy points.
Signed-off-by: NDaniel Stone <daniels@collabora.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213181912.92904-1-daniels@collabora.com

We need to define DRM_FORMAT_MOD_VENDOR_NONE for the fourcc_mod_code()
macro to work correctly.
Signed-off-by: NKristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1481657272-25975-1-git-send-email-hoegsberg@google.com

drm_put_dev is the old midlayer-broken device cleanup function, but
etnaviv has a proper unbind function which first unregisters and then
drops the final reference. No functional change since
drm_dev_unregister happens to be idempotent.

Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161208110739.24417-1-daniel.vetter@ffwll.ch

fsl is already fully demidlayered in the probe function, but for
convenience stuck with drm_put_dev. Call the unregister/unref parts
separately, to make sure this driver works correct.

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: CK Hu <ck.hu@mediatek.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161208110739.24417-3-daniel.vetter@ffwll.ch

- Put all the remaing bits of the old doc into suitable places in the
  new sphinx world.
- Also document the poll support, we forgot to do that.
- Delete dma-buf-sharing.txt.

v2: Don't forget to update MAINTAINERS.

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/20161209215055.3492-1-daniel.vetter@ffwll.ch

- 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