Some data were put into a sequence by separate function calls.
Print the same data by five single function calls instead.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1f5c5b0d-77c4-6efc-7906-cee76c33d2b0@users.sourceforge.net

gdp_dbg_ctl() uses seq_printf() to display a color format name even
though there is no format string. When using -Wformat-string, gcc
reports the following warning:

    drivers/gpu/drm/sti/sti_gdp.c: In function 'gdp_dbg_ctl':
    drivers/gpu/drm/sti/sti_gdp.c:150:18: warning: format not a string
    literal and no format arguments [-Wformat-security]
        seq_printf(s, gdp_format_to_str[i].name);
                      ^~~~~~~~~~~~~~~~~

Silence this warning by using seq_puts() instead.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170331192507.20538-1-nicolas.iooss_linux@m4x.org

With all drivers converted there's only legacy dri1 drivers using it.
Not going to touch those, instead just hide it like we've done with
other dri1 driver hooks like firstopen.

In all this I didn't find any real reason why we'd needed 2 hooks, and
having symmetry between open and close just appeases my OCD better.
Yeah, someone else could do an s/postclose/close/, but that's for
someone who understands cocci. And maybe after this series is reviewed
and landed, to avoid patch-regen churn.

v2: s/last/post/close in the kernel-doc (Sean).
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508082633.4214-4-daniel.vetter@ffwll.ch

Again no apparent explanation for the split except hysterical raisins.
Merging them also makes it a bit more obviuos what's going on wrt the
runtime pm refdancing.

Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508082633.4214-3-daniel.vetter@ffwll.ch

I didn't spot anything that would require ordering here (well not
anywhere else either), and I'm trying to unify at least modern drivers
on one close hook.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508082633.4214-2-daniel.vetter@ffwll.ch

Again no apparent explanation for the split except hysterical raisins.
Merging them also makes it a bit more obviuos what's going on wrt the
runtime pm refdancing.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508082633.4214-1-daniel.vetter@ffwll.ch

This is a modesetting driver for the pl111 CLCD display controller
found on various ARM platforms such as the Versatile Express. The
driver has only been tested on the bcm911360_entphn platform so far,
with PRIME-based buffer sharing between vc4 and clcd.

It reuses the existing devicetree binding, while not using quite as
many of its properties as the fbdev driver does (those are left for
future work).

v2: Nearly complete rewrite by anholt, cutting 2/3 of the code thanks
    to DRM core's excellent new helpers.
v3: Don't match pl110 any more, don't attach if we don't have a DRM
    panel, use DRM_GEM_CMA_FOPS, update MAINTAINERS, use the simple
    display helper, use drm_gem_cma_dumb_create (same as our wrapper).
v4: Change the driver's .name to not clash with fbdev in sysfs, drop
    platform alias, drop redundant "drm" in DRM driver name, hook up
    .prepare_fb to the CMA helper so that DMA fences should work.
v5: Move register definitions inside the driver directory, fix build
    in COMPILE_TEST and !AMBA mode.
v6: Drop TIM2_CLKSEL for now to be consistent with existing DT
    bindings, switch back to external register definitions.
Signed-off-by: Tom Cooksey <tom.cooksey@arm.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> (v5)
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170413031746.12921-2-eric@anholt.net

We'd like to reuse these register definitions for the DRM CLCD driver,
but there's a bunch of fbdev-specific code in the current header.

v2: Add #ifndef guard.
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170413031746.12921-1-eric@anholt.net

Cygnus has V3D 2.6 instead of 2.1, and doesn't use the VC4 display
modules.  The V3D can be uniquely identified by the IDENT[01]
registers, and there's nothing to key off of for the display change
other than the lack of DT nodes for the display components, but it's
convention to have new compatible strings anyway.
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170428224223.21904-3-eric@anholt.net

There's no sense in having an fbdev if there's no display, since
connectors don't get hotplugged to this hardware.  On Cygnus we were
getting a dmesg error from passing in num_connectors (0), when that
argument is supposed to be the maximum number of cloned connectors per
CRTC (1).
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170428224223.21904-2-eric@anholt.net

For the Raspberry Pi's bindings, the power domain also implicitly
turns on the clock and deasserts reset, but for the new Cygnus port we
start representing the clock in the devicetree.

v2: Document the clock-names property, check for -ENOENT for no clock
    in DT.
v3: Drop NULL checks around clk calls which embed NULL checks.
v4: Drop clk-names (feedback by Rob Herring)
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170428224223.21904-1-eric@anholt.net

plane_state can't be NULL anywhere in this function, so the NULL check
at the end is redundant, remove it.

Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1493214013-15580-9-git-send-email-imre.deak@intel.comReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Three single characters (line breaks) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/b8a85220-039a-e4bb-c74b-d76baab234e8@users.sourceforge.net

The script "checkpatch.pl" pointed information out like the following.

Comparison to NULL could be written "!attach"

Thus adjust this expression.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

A bit of data was put into a sequence by two separate function calls.
Print the same data by a single function call instead.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

Some connectors may not allow all scaling mode properties, this function will allow
creating the scaling mode property with only the supported subset. It also wires up
this state for atomic.

This will make it possible to convert i915 connectors to atomic.

Changes since v1:
 - Add DRM_MODE_PROP_ENUM flag to drm_property_create
 - Use the correct index in drm_property_add_enum.
 - Add DocBook for function (Sean Paul).
 - Warn if less than 2 valid scaling modes are passed.
 - Remove level of indent. (Sean Paul)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170501133804.8116-3-maarten.lankhorst@linux.intel.com
[mlankhorst: Rename function, fix docbook issues]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This is only used in i915, which had used its own non-atomic way to
deal with the picture aspect ratio. Move selected aspect_ratio to
atomic state and use the atomic state in the affected i915 connectors.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170501133804.8116-2-maarten.lankhorst@linux.intel.com
[mlankhorst: taomic -> atomic thanks to Manasi's input]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Enable the GEM dma-buf import interfaces in addition to the export
interfaces. This lets vgem be used as a test source for other allocators
(e.g. Ion).
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1493923548-20878-4-git-send-email-labbott@redhat.com

The existing drm_gem_prime_import function uses the underlying
struct device of a drm_device for attaching to a dma_buf. Some drivers
(notably vgem) may not have an underlying device structure. Offer
an alternate function to attach using any available device structure.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1493923548-20878-3-git-send-email-labbott@redhat.com

The vgem driver is currently registered independent of any actual
device. Some usage of the dmabuf APIs require an actual device structure
to do anything. Register a dummy platform device for use with dmabuf.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1493923548-20878-2-git-send-email-labbott@redhat.com

Use the added helpers to track MST link bandwidth for atomic modesets.
Link bw is acquired in the ->atomic_check() phase when CRTCs are being
enabled with drm_atomic_find_vcpi_slots(). Similarly, link bw is released
during ->atomic_check() with the connector helper callback ->atomic_check()
when CRTCs are disabled.

v6: active_changed does not alter vcpi allocations (Maarten)
v5: Implement connector->atomic_check() in place of atomic_release()
v4: Return an int from intel_dp_mst_atomic_release() (Maarten)
v3:
 Handled the case where ->atomic_release() is called more than once
 during an atomic_check() for the same state.
v2:
 Squashed atomic_release() implementation and caller (Daniel)
 Fixed logic for connector-crtc switching case (Daniel)
 Fixed logic for suspend-resume case.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <Harry.wentland@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1493421260-3146-1-git-send-email-dhinakaran.pandiyan@intel.com

drm_dp_atomic_find_vcpi_slots() should be called from ->atomic_check() to
check there are sufficient vcpi slots for a mode and to add that to the
state. This should be followed by a call to drm_dp_mst_allocate_vcpi()
in ->atomic_commit() to initialize a struct vcpi for the port.

drm_dp_atomic_release_vcpi_slots() should be called from
->atomic_check() to release a port's vcpi slot allocation from the
state.

Drivers that do not make use of this atomic helper are expected to call
drm_dp_find_vcpi_slots() instead before calling
drm_dp_mst_allocate_vcpi().

v3: drm_dp_atomic_release_vcpi_slots() now needs to know how many slots
    to release as we may not have a valid reference to port.
v2:
Added checks for verifying the port reference is valid
Moved get_mst_topology_state() into the helpers (Daniel)
Changed find_vcpi_slots() to not depend on current allocation

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <Harry.wentland@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1492753893-3748-4-git-send-email-dhinakaran.pandiyan@intel.com

Link bandwidth is shared between multiple display streams in DP MST
configurations. The DP MST topology manager structure maintains the
shared link bandwidth for a primary link directly connected to the GPU. For
atomic modesetting drivers, checking if there is sufficient link bandwidth
for a mode needs to be done during the atomic_check phase to avoid failed
modesets. Let's encapsulate the available link bw information in a
private state structure so that bw can be allocated and released atomically
for each of the ports sharing the primary link.

v3: WARN_ON() if connection_mutex is not held (Archit)
v2: Included kernel doc, moved state initialization and switched to
kmemdup() for allocation (Daniel)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <Harry.wentland@amd.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1492753893-3748-3-git-send-email-dhinakaran.pandiyan@intel.com

It is necessary to track states for objects other than connector, crtc
and plane for atomic modesets. But adding objects like DP MST link
bandwidth to drm_atomic_state would mean that a non-core object will be
modified by the core helper functions for swapping and clearing
it's state. So, lets add void * objects and helper functions that operate
on void * types to keep these objects and states private to the core.
Drivers can then implement specific functions to swap and clear states.
The other advantage having just void * for these objects in
drm_atomic_state is that objects of different types can be managed in the
same state array.

v7: Use __for_each_private_obj to define for_each_private_obj (Maarten)
v6: More kernel-doc to keep 0-day happy
v5: Remove more NULL checks (Maarten)
v4: Avoid redundant NULL checks when private_objs array is empty (Maarten)
v3: Macro alignment (Chris)
v2: Added docs and new iterator to filter private objects (Daniel)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Harry Wentland <Harry.wentland@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1492753893-3748-2-git-send-email-dhinakaran.pandiyan@intel.com

Backmerging Dave's 'drm-for-v4.12' pull request now that it's landed. There are
a bunch of non-drm changes which are just random bits we hadn't yet picked up in
misc-next.

main drm pull request for 4.12 kernel
Signed-off-by: Sean Paul <seanpaul@chromium.org>

Link: http://patchwork.freedesktop.org/patch/msgid/CAPM=9ty0jHgzG18zOr5CYODyTqZfH55kOCOFqNnXiWnTb_uNWw@mail.gmail.com

Scatter a few cond_resched() in between phases of the drm_mm selftests
to try and prevent us incurring the wrath of the NMI watchdog.
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>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170329091053.13837-1-chris@chris-wilson.co.uk

It adds VGA driver support, which needs to configure corresponding VOU
interface in RGB_888 format, and thus the following changes are needed
on zx_vou.

 - Rename the CSC block of Graphic Layer a bit to make it more specific,
   and add CSC of Channel to support RGB output.
 - Bypass Dither block for RGB output.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1491910226-7831-1-git-send-email-shawnguo@kernel.org

It adds bindings doc for ZTE VOU VGA output device.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1491490870-6330-4-git-send-email-shawnguo@kernel.org

The CSC (Color Space Conversion) block in VOU is used by not only
Graphic Layer (plane) but also channel (CRTC) module.  Let's move
its register definitions into a common header, so that CRTC driver can
include it when needed.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1491490870-6330-3-git-send-email-shawnguo@kernel.org

Some VOU modules do not work well with clock auto-gating.  For example,
VGA I2C bus will fail to read EDID data from monitor.  Let's not enable
this feature by default, and leave it to the possible future low-power
optimization.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1491490870-6330-2-git-send-email-shawnguo@kernel.org

Use "non-blocking" and "blocking" instead of old names.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170427143506.32650-1-gustavo@padovan.org

Remove unused check and variables after:
drm/rockchip: Set line flag config register in vop_crtc_enable
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1493469547-2121-1-git-send-email-jeffy.chen@rock-chips.com

Change drm_atomic_replace_property_blob_from_id()'s first parameter
from drm_crtc to drm_device, so that the function can be used for other
drm_mode_objects too.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/851b8504c7f294a10645ba6f6d391ac9764068b7.1492768073.git.jsarha@ti.com

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/69c913b3ae3fc7235c059e08f58fb0a172d98cf8.1492768073.git.jsarha@ti.com

Some nouveau regression fixes.

* 'linux-4.12' of git://github.com/skeggsb/linux:
  drm/nouveau/fb/gf100-: Fix 32 bit wraparound in new ram detection
  drm/nouveau/secboot/gm20b: fix the error return code in gm20b_secboot_tegra_read_wpr()
  drm/nouveau/kms: Increase max retries in scanout position queries.
  drm/nouveau/bios/bitP: check that table is long enough for optional pointers
  drm/nouveau/fifo/nv40: no ctxsw for pre-nv44 mpeg engine

A missing u64 cast causes a 32-Bit wraparound from
4096 MiB to 0 MiB and therefore total 0 MiB VRAM detected
if card has 4096 Mib per FBP.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Karol Herbst <karolherbst@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

The error return code PTR_ERR(mc) is always 0 since mc is
equal to 0 in this error handling case.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

So far we only allowed for 1 retry and just failed the query
- and thereby high precision vblank timestamping - if we did
not get a reasonable result, as such a failure wasn't considered
all too horrible. There are a few NVidia gpu models out there which
may need a bit more than 1 retry to get a successful query result
under some conditions.

Since Linux 4.4 the update code for vblank counter and timestamp
in drm_update_vblank_count() changed so that the implementation
assumes that high precision vblank timestamping of a kms driver
either consistently succeeds or consistently fails for a given
video mode and encoder/connector combo. Iow. switching from success
to fail or vice versa on a modeset or connector change is ok, but
spurious temporary failure for a given setup can confuse the core
code and potentially cause bad miscounting of vblanks and confusion
or hangs in userspace clients which rely on vblank  stuff, e.g.,
desktop compositors.

Therefore change the max retry count to a larger number - more than
any gpu so far is known to need to succeed, but still low enough
so that these queries which do also happen in vblank interrupt are
still fast enough to be not disastrously long if something would
go badly wrong with them.

As such sporadic retries only happen seldom even on affected gpu's,
this could mean a vblank irq could take a few dozen microseconds
longer every few hours of uptime -- better than a desktop compositor
randomly hanging every couple of hours or days of uptime in a hard
to reproduce manner.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Fixes OOB VBIOS accesses on some boards.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>