Now the bind functions have all the protection explicitly the
drivers can just call them directly, and the api can be unexported
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917043040.146575-5-airlied@gmail.com

This moves unbind into the driver side on destroy paths.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917043040.146575-4-airlied@gmail.com

Call the driver first and have it call the common code cleanup.

This is useful later to fix unbind.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917043040.146575-3-airlied@gmail.com

This moves the generic tracking into the drivers and protects
against reentrancy in the drivers. It fixes up radeon and agp
to be able to query the bound status as that is required.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917043040.146575-2-airlied@gmail.com

Unexport ttm_check_under_lowerlimit.
Make ttm_bo_acc_size static and unexport it.
Remove ttm_get_kernel_zone_memory_size.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/390515/

An active cursor plane requires a valid display mode. Change the
commit_tail callback, so that it sets up the CRTC's mode before
updating planes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200914072236.19398-5-tzimmermann@suse.de

This change simplifies ast's modesetting code. The display mode
is now programmed from within the CRTC's atomic_enable(), which
only runs if we actually want to program the mode.

Corresponding code in atomic_flush() is being removed. Also removed
is atomic_begin(), which serves no purpose at all.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200914072236.19398-4-tzimmermann@suse.de

The ast HW cursor requires the primary plane and CRTC to display at
a valid mode and format. This is not the case while switching
display modes, which can lead to the screen turing permanently dark.

As a workaround, the ast driver now disables active planes while the
mode or format switch takes place. It also synchronizes with the vertical
refresh to give CRTC and planes some time to catch up on each other.
The active planes planes (primary or cursor) will be re-enabled by
each plane's atomic_update() function.

v3:
	* move the logic into the CRTC's atomic_disable function
v2:
	* move the logic into the commit-tail function
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200914072236.19398-3-tzimmermann@suse.de

The atomic modesetting code tried to distinguish format changes from
full modesetting operations. But the implementation was buggy and the
format registers were often updated even for simple pageflips.

Fix this problem by handling format changes in the primary plane's
update function.

v3:
	* program format in primary plane's update function
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200914072236.19398-2-tzimmermann@suse.de

The lcdif IP does not support a framebuffer pitch (stride) other than
framebuffer width. Check for equality and reject the framebuffer
otherwise.

This prevents a distorted picture when using 640x800 and running the
Mesa graphics stack. Mesa tries to use a cache aligned stride, which
leads at that particular resolution to width != stride. Currently
Mesa has no fallback behavior, but rejecting this configuration allows
userspace to handle the issue correctly.

Fixes: 45d59d70 ("drm: Add new driver for MXSFB controller")
Signed-off-by: NStefan Agner <stefan@agner.ch>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200908141654.266836-1-stefan@agner.ch

Handing the return value of drm_universal_plane_init to fix the following
W=1 kernel build warning(s):
vc4_plane.c: In function ‘vc4_plane_init’:
vc4_plane.c:1340:6: warning: variable ‘ret’ set but not
used [-Wunused-but-set-variable]
Signed-off-by: NTian Tao <tiantao6@hisilicon.com>
Reviewed-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/1599811777-34093-1-git-send-email-tiantao6@hisilicon.com

Move bound up into the bo object, and keep populated with the tt
object.

The ghost object handling needs to follow the flags at the bo
level now instead of it being part of the ttm tt object.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915024007.67163-7-airlied@gmail.com

Move these up to the bo level, moving ttm_tt to just being
backing store. Next step is to move the bound flag out.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915024007.67163-6-airlied@gmail.com

Drivers have to call populate themselves now before binding.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915024007.67163-5-airlied@gmail.com

This just makes things easier later.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915024007.67163-4-airlied@gmail.com

All places this was called was using bo->ttm either direct
or indirectly.

v2: move to ttm_bo
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915024007.67163-3-airlied@gmail.com

This adds 2 getters and 4 setters, however unbound and populated
are currently the same thing, this will change, it also drops
a BUG_ON that seems not that useful.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200915024007.67163-2-airlied@gmail.com

Instead of letting TTM make an educated guess based on
some mask all drivers should just specify what caching
they want for their CPU mappings.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/390207/

Instead of letting TTM masking the caching bits
specify directly what the driver needs.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/390206

As far as I can tell this was never used either and we just
always fallback to the order cached > wc > uncached anyway.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/390142/

The get_edid() callback can be triggered anytime by an ioctl, i.e

  drm_mode_getconnector (ioctl)
    -> drm_helper_probe_single_connector_modes
       -> drm_bridge_connector_get_modes
          -> ps8640_bridge_get_edid

Actually if the bridge pre_enable() function was not called before
get_edid(), the driver will not be able to get the EDID properly and
display will not work until a second get_edid() call is issued and if
pre_enable() is called before. The side effect of this, for example, is
that you see anything when `Frecon` starts, neither the splash screen,
until the graphical session manager starts.

To fix this we need to make sure that all we need is enabled before
reading the EDID. This means the following:

1. If get_edid() is called before having the device powered we need to
   power on the device. In such case, the driver will power off again the
   device.

2. If get_edid() is called after having the device powered, all should
   just work. We added a powered flag in order to avoid recurrent calls
   to ps8640_bridge_poweron() and unneeded delays.

3. This seems to be specific for this device, but we need to make sure
   the panel is powered on before do a power on cycle on this device.
   Otherwise the device fails to retrieve the EDID.
Signed-off-by: NEnric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: NBilal Wasim <bwasim.lkml@gmail.com>
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200827085911.944899-2-enric.balletbo@collabora.com

Usually we wait for the host to complete the unref request, then cleanup
the guest-side state of the object in the completion callback.  When
submitting the unref command failed the completion callback will not be
called though, so cleanup right away.

Fixes a WARN on stale mm entries on driver shutdown.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NGurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200908070723.6394-4-kraxel@redhat.com

In case queuing virtio commands fails (can happen when
the device got unplugged) pass up the error.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NGurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200908070723.6394-3-kraxel@redhat.com

Use managed init call to simplify cleanup.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NGurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200908070723.6394-2-kraxel@redhat.com

Ingenic SoCs are most notably used in cheap chinese handheld gaming
consoles. There, the games and applications generally render in software
directly into GEM buffers.

Traditionally, GEM buffers are mapped write-combine. Writes to the
buffer are accelerated, and reads are slow. Application doing lots of
alpha-blending paint inside shadow buffers, which is then memcpy'd into
the final GEM buffer.

On recent Ingenic SoCs however, it is much faster to have a fully cached
GEM buffer, in which applications paint directly, and whose data is
invalidated before scanout, than having a write-combine GEM buffer, even
when alpha blending is not used.

Add an optional 'cached_gem_buffers' parameter to the ingenic-drm driver
to allow GEM buffers to be mapped fully-cached, in order to speed up
software rendering.

v2: Use standard noncoherent DMA APIs

v3: Use damage clips instead of invalidating full frames

v4: Avoid dma_pgprot() which is not exported. Using vm_get_page_prot()
    is enough in this case.

v5:
- Avoid calling drm_gem_cma_prime_mmap(). It has the side effect that an
  extra object reference is obtained, which causes our dumb buffers to
  never be freed. It should have been drm_gem_cma_mmap_obj(). However,
  our custom mmap function only differs with one flag, so we can cleanly
  handle both modes in ingenic_drm_gem_mmap().
- Call drm_gem_vm_close() if drm_mmap_attrs() failed, just like in
  drm_gem_cma_mmap_obj().
Signed-off-by: NPaul Cercueil <paul@crapouillou.net>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200912195639.176001-1-paul@crapouillou.net

We update the timestamping constants per-crtc explicitly in
intel_crtc_update_active_timings(). Furtermore the helper will
use uapi.adjusted_mode whereas we want hw.adjusted_mode. Thus
let's drop the helper call an rely on what we already have in
intel_crtc_update_active_timings(). We can now also drop the
hw.adjusted_mode -> uapi.adjusted_mode copy hack that was added
to keep the helper from deriving the timestamping constants from
the wrong thing.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200907120026.6360-3-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drm/atomic-helper: Remove the timestamping constant update from drm_atomic_helper_update_legacy_modeset_state()

The timestamping constants have nothing to do with any legacy state
so should not be updated from
drm_atomic_helper_update_legacy_modeset_state().

Let's make everyone call drm_atomic_helper_calc_timestamping_constants()
directly instead of relying on
drm_atomic_helper_update_legacy_modeset_state() to call it.

@@
expression S;
@@
- drm_atomic_helper_calc_timestamping_constants(S);

@@
expression D, S;
@@
  drm_atomic_helper_update_legacy_modeset_state(D, S);
+ drm_atomic_helper_calc_timestamping_constants(S);

v2: Update drm_crtc_vblank_helper_get_vblank_timestamp{,_internal}() docs (Daniel)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200907120026.6360-2-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Put the vblank timestamping constants update loop into its own
function. It has no business living inside
drm_atomic_helper_update_legacy_modeset_state() so we'll be wanting
to move it out entirely. As a first step we'll still call it
from drm_atomic_helper_update_legacy_modeset_state().

v2: Drop comment about 'legacy state' in the new function
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200907120026.6360-1-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I got a use-after-free report when doing some fuzz test:

If ttm_bo_init() fails, the "gbo" and "gbo->bo.base" will be
freed by ttm_buffer_object_destroy() in ttm_bo_init(). But
then drm_gem_vram_create() and drm_gem_vram_init() will free
"gbo" and "gbo->bo.base" again.

BUG: KMSAN: use-after-free in drm_vma_offset_remove+0xb3/0x150
CPU: 0 PID: 24282 Comm: syz-executor.1 Tainted: G    B   W         5.7.0-rc4-msan #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
Call Trace:
 __dump_stack
 dump_stack+0x1c9/0x220
 kmsan_report+0xf7/0x1e0
 __msan_warning+0x58/0xa0
 drm_vma_offset_remove+0xb3/0x150
 drm_gem_free_mmap_offset
 drm_gem_object_release+0x159/0x180
 drm_gem_vram_init
 drm_gem_vram_create+0x7c5/0x990
 drm_gem_vram_fill_create_dumb
 drm_gem_vram_driver_dumb_create+0x238/0x590
 drm_mode_create_dumb
 drm_mode_create_dumb_ioctl+0x41d/0x450
 drm_ioctl_kernel+0x5a4/0x710
 drm_ioctl+0xc6f/0x1240
 vfs_ioctl
 ksys_ioctl
 __do_sys_ioctl
 __se_sys_ioctl+0x2e9/0x410
 __x64_sys_ioctl+0x4a/0x70
 do_syscall_64+0xb8/0x160
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4689b9
Code: fd e0 fa ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb e0 fa ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f368fa4dc98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000076bf00 RCX: 00000000004689b9
RDX: 0000000020000240 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000004d17e0 R14: 00007f368fa4e6d4 R15: 000000000076bf0c

Uninit was created at:
 kmsan_save_stack_with_flags
 kmsan_internal_poison_shadow+0x66/0xd0
 kmsan_slab_free+0x6e/0xb0
 slab_free_freelist_hook
 slab_free
 kfree+0x571/0x30a0
 drm_gem_vram_destroy
 ttm_buffer_object_destroy+0xc8/0x130
 ttm_bo_release
 kref_put
 ttm_bo_put+0x117d/0x23e0
 ttm_bo_init_reserved+0x11c0/0x11d0
 ttm_bo_init+0x289/0x3f0
 drm_gem_vram_init
 drm_gem_vram_create+0x775/0x990
 drm_gem_vram_fill_create_dumb
 drm_gem_vram_driver_dumb_create+0x238/0x590
 drm_mode_create_dumb
 drm_mode_create_dumb_ioctl+0x41d/0x450
 drm_ioctl_kernel+0x5a4/0x710
 drm_ioctl+0xc6f/0x1240
 vfs_ioctl
 ksys_ioctl
 __do_sys_ioctl
 __se_sys_ioctl+0x2e9/0x410
 __x64_sys_ioctl+0x4a/0x70
 do_syscall_64+0xb8/0x160
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

If ttm_bo_init() fails, the "gbo" will be freed by
ttm_buffer_object_destroy() in ttm_bo_init(). But then
drm_gem_vram_create() and drm_gem_vram_init() will free
"gbo" again.
Reported-by: NHulk Robot <hulkci@huawei.com>
Reported-by: Nbutt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: NJia Yang <jiayang5@huawei.com>
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200714083238.28479-2-tzimmermann@suse.de

VRAM helpers support ref counting for pin and vmap operations, no need
to avoid these operations by employing the internal kmap interface. Just
use drm_gem_vram_vmap() and let it handle the details.

Also unexport the kmap interfaces from VRAM helpers. Vboxvideo was the
last user of these internal functions.

v2:
	* fixed a comma in commit description
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: NHans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200911075922.19317-1-tzimmermann@suse.de

This addresses the following gcc warning with "make W=1":

drivers/gpu/drm/xlnx/zynqmp_disp.c:245:18: warning:
‘scaling_factors_666’ defined but not used [-Wunused-const-variable=]
  245 | static const u32 scaling_factors_666[] = {
      |                  ^~~~~~~~~~~~~~~~~~~
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NHyun Kwon <hyun.kwon@xilinx.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200910140630.1191782-1-yanaijie@huawei.com

The Amlogic D-PHY in the Amlogic AXG SoC Family does support a frequency
higher than 10MHz for the TX Escape Clock, thus make the target rate
configurable.
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: NPhilippe Cornu <philippe.cornu@st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200904125531.15248-1-narmstrong@baylibre.com

kmemdup can be used instead of kmalloc+memcpy. Replace an occurrence of
this pattern.

Issue identified with Coccinelle.
Signed-off-by: NAlex Dewar <alex.dewar90@gmail.com>
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200909190213.156302-1-alex.dewar90@gmail.com

It's not supported to specify more than one of those flags.
So it never made sense to make this a flag in the first place.

Nuke the flags and specify directly which memory type to use.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389826/?series=81551&rev=1

Setting more than one placement flag is illegal.
Fix this by using the current flags.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389824/?series=81551&rev=1

Those are going to be removed, stop using them here.

Instead use the GEM flags from the UAPI.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389825/?series=81551&rev=1

Those are going to be removed, stop using them here.

Instead define separate flags for the helper.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389823/?series=81551&rev=1

Clang warns:

drivers/gpu/drm/vc4/vc4_plane.c:901:27: warning: operator '?:' has lower
precedence than '|'; '|' will be evaluated first
[-Wbitwise-conditional-parentheses]
                                fb->format->has_alpha ?
                                ~~~~~~~~~~~~~~~~~~~~~ ^
drivers/gpu/drm/vc4/vc4_plane.c:901:27: note: place parentheses around
the '|' expression to silence this warning
                                fb->format->has_alpha ?
                                ~~~~~~~~~~~~~~~~~~~~~ ^
drivers/gpu/drm/vc4/vc4_plane.c:901:27: note: place parentheses around
the '?:' expression to evaluate it first
                                fb->format->has_alpha ?
                                ~~~~~~~~~~~~~~~~~~~~~~^
1 warning generated.

Add the parentheses as that was clearly intended, otherwise
SCALER5_CTL2_ALPHA_PREMULT won't be added to the list.

Fixes: c54619b0 ("drm/vc4: Add support for the BCM2711 HVS5")
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1150Signed-off-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200910171831.4112580-1-natechancellor@gmail.com

Clang warns 100+ times in the vc4 driver along the lines of:

drivers/gpu/drm/vc4/vc4_hdmi_phy.c:518:13: warning: implicit conversion
from enumeration type 'enum vc4_hdmi_field' to different enumeration
type 'enum vc4_hdmi_regs' [-Wenum-conversion]
        HDMI_WRITE(HDMI_TX_PHY_POWERDOWN_CTL,
        ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

The HDMI_READ and HDMI_WRITE macros pass in enumerators of type
vc4_hdmi_field but vc4_hdmi_write and vc4_hdmi_read expect a enumerator
of type vc4_hdmi_regs, causing a warning for every instance of this.
Update the parameter type so there is no more mismatch.

Fixes: 311e305f ("drm/vc4: hdmi: Implement a register layout abstraction")
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1149Signed-off-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200910170401.3857250-1-natechancellor@gmail.com

This function always return '0' and no callers use the return value. So
make it a void function.

This eliminates the following coccicheck warning:

drivers/gpu/drm/i810/i810_dma.c:860:8-11: Unneeded variable: "ret".
Return "0" on line 885
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200910140610.1191578-1-yanaijie@huawei.com