The function's behaviour was changed in 90844f00, without changing
its signature, causing people to keep using it the old way without
realising they were now leaking memory.
Rob Clark also noticed it was also allocating GFP_KERNEL memory in
atomic contexts, breaking them.

Instead of having to allocate GFP_ATOMIC memory and fixing the callers
to make them cleanup the memory afterwards, let's change the function's
signature by having the caller take care of the memory and passing it to
the function.
The new parameter is a single-field struct in order to enforce the size
of its buffer and help callers to correctly manage their memory.

Fixes: 90844f00 ("drm: make drm_get_format_name thread-safe")
Cc: Rob Clark <robdclark@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NRob Clark <robdclark@gmail.com>
Acked-by: Sinclair Yeh <syeh@vmware.com> (vmwgfx)
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NEric Engestrom <eric@engestrom.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161112011309.9799-1-eric@engestrom.ch

I screwed up rebasing of my patch in

commit 43968d7b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Sep 21 10:59:24 2016 +0200

    drm: Extract drm_plane.[hc]

which meant on error paths drm_crtc_vblank_put could be called without
a get, leading to an underrun of the refcount.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98020Reported-and-tested-by: NAndy Furniss <adf.lists@gmail.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Michel Dänzer <michel@daenzer.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161003082827.11586-1-daniel.vetter@ffwll.chSigned-off-by: NDave Airlie <airlied@redhat.com>

Commit 43968d7b ("drm: Extract drm_plane.[hc]") was not the simple
cut'n'paste we presumed, somehow it introduced a leak of the page flip
target's framebuffer.

Fixes: 43968d7b ("drm: Extract drm_plane.[hc]")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160928222500.11827-1-chris@chris-wilson.co.ukSigned-off-by: NDave Airlie <airlied@redhat.com>

Try to spec a bit more precisely how they all fit together, now that
at least the code is for all the additional properties is in one
place.

Also remove the entries for the standardized properties from the
table, because that thing is supremely unmaintaineable.

v2: Fix typos Sean spotted.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474448370-32227-4-git-send-email-daniel.vetter@ffwll.ch

Big thing is untangling and carefully documenting the different uapi
types of planes. I also sprinkled a few more cross references around
to make this easier to discover.

As usual, remove the kerneldoc for internal functions which are not
exported. Aside: We should probably go OCD on all the ioctl handlers
and consistenly give them an _ioctl postfix.
Acked-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1474448370-32227-2-git-send-email-daniel.vetter@ffwll.ch

Just pure code movement, cleanup and polish will happen in later
patches.

v2: Don't forget all the ioctl! To extract those cleanly I decided to
put check_src_coords into drm_framebuffer.c (and give it a
drm_framebuffer_ prefix), since that just checks framebuffer
constraints.

v3: rebase over PAGE_FLIP_TARGET.
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

[seanpaul]
This patch as posted on the list was rebased on:

commit 6f00975c
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Aug 20 12:22:11 2016 +0200

    drm: Reject page_flip for !DRIVER_MODESET

so as a result of moving the page_flip ioctl, this fix has
been rolled into this patch.
Signed-off-by: NSean Paul <seanpaul@chromium.org>