We have serious dangling else bugs waiting to happen in our for_each_
style macros with ifs. Consider, for example,

 #define for_each_power_domain(domain, mask)                         \
         for ((domain) = 0; (domain) < POWER_DOMAIN_NUM; (domain)++) \
                 if ((1 << (domain)) & (mask))

If this is used in context:

	if (condition)
		for_each_power_domain(domain, mask);
	else
		foo();

foo() will be called for each domain *not* in mask, if condition holds,
and not at all if condition doesn't hold.

Fix this by reversing the conditions in the macros, and adding an else
branch for the "for each" block, so that other if/else blocks can't
interfere. Provide a "for_each_if" helper macro to make it easier to get
this right.

v2: move for_each_if to drmP.h in a separate patch.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448392916-2281-2-git-send-email-jani.nikula@intel.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To avoid even more code duplication punt this all to the probe worker,
which needs some slight adjustment to also generate a uevent when the
status has changed to due connector->force.

v2: Instead of running the output_poll_work (which is kinda the wrong
thing and a layering violation since it's an internal of the probe
helpers), or calling ->detect (which is again a layering violation
since it's used only by probe helpers) just call the official
->fill_modes function, like a GET_CONNECTOR ioctl call.

v3: Restore the accidentally removed forced-probe for echo "detect" >
force.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447951610-12622-22-git-send-email-daniel.vetter@ffwll.chReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the correct function name for drm_atomic_clean_old_fb docs.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We chase pointers/lists without taking the locks protecting them,
which isn't that good.

Fix it.

v2: Actually unlock properly, spotted by Julia.

v3: Put the label _before_ the mutex_unlock (Emil)

Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Link: http://patchwork.freedesktop.org/patch/msgid/1443783662-23066-1-git-send-email-daniel.vetter@ffwll.chReviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To aid in debugging failures, print the src,dst,clip rectangles
when drm_plane_helper_check_update() fails.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Allow the caller to specify a "prefix" string to drm_rect_debug_print()
to make it easier to see which drm_rect is being printed.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Drivers shouldn't clobber the passed in addfb ioctl parameters.
i915 was doing just that. To prevent it from happening again,
pass the struct around as const, starting all the way from
internal_framebuffer_create().
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The simple_strtoul function is marked as obsolete.
This patch replace it by kstrtouint.
Signed-off-by: NLABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I noticed that intel_fbdev->our_mode is unused. Introduced by
79e53945 ("DRM: i915: add mode setting support").

Then I noticed that intel_fbdev->fbdev_list is unused as well.
Introduced by 38651674 ("drm/fb: fix fbdev object model +
cleanup properly.") in i915, nouveau and radeon.

Subsequently cargo culted to amdgpu, ast, cirrus, qxl, udl,
virtio and mgag200.

Already removed from the latter with cc59487a ("drm/mgag200:
'fbdev_list' in 'struct mga_fbdev' is not used").

Remove it from the others.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The drm_property_unreference_blob() function tests whether its argument
is NULL and then returns immediately.
Thus the tests around the calls are not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Link: http://patchwork.freedesktop.org/patch/msgid/563C8B3E.405@users.sourceforge.netSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

DRM_TEGRA_FBDEV config is currently used to enable/disable legacy fbdev
emulation for the tegra kms driver.

Remove this local config option and use the top level DRM_FBDEV_EMULATION
config option instead.
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1445933459-5249-4-git-send-email-architt@codeaurora.orgSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

DRM_IMX_FB_HELPER config is currently used to enable/disable fbdev
emulation for the imx kms driver.

Remove this local config option and use the top level DRM_FBDEV_EMULATION
config option where applicable. Using this config lets us also prevent
wrapping around drm_fb_helper_* calls with #ifdefs in certain places.
Tested-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1445933459-5249-2-git-send-email-architt@codeaurora.orgSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A bunch of things have been removed meanwhile and docs not fully
brought up to speed. And a few gaps closed where I noticed missing
kerneldoc while reading through the overview sections.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445533889-7661-3-git-send-email-daniel.vetter@ffwll.chReviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was totally lost when I originally created the atomic helpers.

We probably should also check possible_clones in the helpers, but
since the legacy ones didn't do that this is for a separate patch.
Reported-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Stone <daniels@collabora.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447868808-10266-1-git-send-email-daniel.vetter@ffwll.ch

This reverts

commit 6764e9f8
Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date:   Thu Aug 27 15:44:06 2015 +0200

    drm/i915: skip modeset if compatible for everyone.

Bring back the i915.fastboot module parameter, disabled by default, due
to backlight regression on Chromebook Pixel 2015.

Apparently the firmware of the Chromebook in question enables the panel
but disables backlight to avoid a brief garbage scanout upon loading the
kernel/module. With fastboot, we leave the backlight untouched, in this
case disabled. The user would have to do a modeset (i.e. not just crank
up the brightness) to enable the backlight.

There is no clean fix readily available, so get back to the drawing
board by reverting.

[N.B. The reference below is for when the thread was included on public
lists, and some of the context had already been dropped by then.]
Reported-and-tested-by: NOlof Johansson <olof@lixom.net>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
References: http://marc.info/?i=CAKMK7uES7xk05ki92oeX6gmvZWAh9f2vL7yz=6T+fGK9J3X7cQ@mail.gmail.com
Fixes: 6764e9f8 ("drm/i915: skip modeset if compatible for everyone.")
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447921590-3785-1-git-send-email-jani.nikula@intel.com

The machine hang completely with the following message on the console:

[  487.777538] BUG: unable to handle kernel NULL pointer dereference at 0000000000000060
[  487.777554] IP: [<ffffffff8158aaee>] _raw_spin_lock+0xe/0x30
[  487.777557] PGD 42e9f7067 PUD 42f2fa067 PMD 0
[  487.777560] Oops: 0002 [#1] SMP
...
[  487.777618] CPU: 21 PID: 3190 Comm: Xorg Tainted: G            E   4.4.0-rc1-3-default+ #6
[  487.777620] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0059.R00.1501081238 01/08/2015
[  487.777621] task: ffff880853ae4680 ti: ffff8808696d4000 task.ti: ffff8808696d4000
[  487.777625] RIP: 0010:[<ffffffff8158aaee>]  [<ffffffff8158aaee>] _raw_spin_lock+0xe/0x30
[  487.777627] RSP: 0018:ffff8808696d79c0  EFLAGS: 00010246
[  487.777628] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  487.777629] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000060
[  487.777630] RBP: ffff8808696d79e0 R08: 0000000000000000 R09: ffff88086924a780
[  487.777631] R10: 000000000001bb40 R11: 0000000000003246 R12: 0000000000000000
[  487.777632] R13: ffff880463a27360 R14: ffff88046ca50218 R15: 0000000000000080
[  487.777634] FS:  00007f3f81c5a8c0(0000) GS:ffff88086f060000(0000) knlGS:0000000000000000
[  487.777635] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  487.777636] CR2: 0000000000000060 CR3: 000000042e678000 CR4: 00000000001406e0
[  487.777638] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  487.777639] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  487.777639] Stack:
[  487.777642]  ffffffffa00eb5fa ffff8808696d7b60 ffff88086b87d800 0000000000000000
[  487.777644]  ffff8808696d7ac8 ffffffffa01694b6 ffff8808696d7ae8 ffffffff8109c8d5
[  487.777647]  ffff880469158740 ffff880463a27000 ffff88086b87d800 ffff88086b87d800
[  487.777647] Call Trace:
[  487.777674]  [<ffffffffa00eb5fa>] ? drm_gem_object_lookup+0x1a/0xa0 [drm]
[  487.777681]  [<ffffffffa01694b6>] mga_crtc_cursor_set+0xc6/0xb60 [mgag200]
[  487.777691]  [<ffffffff8109c8d5>] ? find_busiest_group+0x35/0x4a0
[  487.777696]  [<ffffffff81086294>] ? __might_sleep+0x44/0x80
[  487.777699]  [<ffffffff815888c2>] ? __ww_mutex_lock+0x22/0x9c
[  487.777722]  [<ffffffffa0104f64>] ? drm_modeset_lock+0x34/0xf0 [drm]
[  487.777733]  [<ffffffffa0148d9e>] restore_fbdev_mode+0xee/0x2a0 [drm_kms_helper]
[  487.777742]  [<ffffffffa014afce>] drm_fb_helper_restore_fbdev_mode_unlocked+0x2e/0x70 [drm_kms_helper]
[  487.777748]  [<ffffffffa014b037>] drm_fb_helper_set_par+0x27/0x50 [drm_kms_helper]
[  487.777752]  [<ffffffff8134560c>] fb_set_var+0x18c/0x3f0
[  487.777777]  [<ffffffffa02a9b0a>] ? __ext4_handle_dirty_metadata+0x8a/0x210 [ext4]
[  487.777783]  [<ffffffff8133cb97>] fbcon_blank+0x1b7/0x2b0
[  487.777790]  [<ffffffff813be2a3>] do_unblank_screen+0xb3/0x1c0
[  487.777795]  [<ffffffff813b5aba>] vt_ioctl+0x118a/0x1210
[  487.777801]  [<ffffffff813a8fe0>] tty_ioctl+0x3f0/0xc90
[  487.777808]  [<ffffffff81172018>] ? kzfree+0x28/0x30
[  487.777813]  [<ffffffff811e053f>] ? mntput+0x1f/0x30
[  487.777817]  [<ffffffff811d3f5d>] do_vfs_ioctl+0x30d/0x570
[  487.777822]  [<ffffffff8107ed3a>] ? task_work_run+0x8a/0xa0
[  487.777825]  [<ffffffff811d4234>] SyS_ioctl+0x74/0x80
[  487.777829]  [<ffffffff8158aeae>] entry_SYSCALL_64_fastpath+0x12/0x71
[  487.777851] Code: 65 ff 0d ce 02 a8 7e 5d c3 ba 01 00 00 00 f0 0f b1 17 85 c0 75 e8 b0 01 5d c3 0f 1f 00 65 ff 05 b1 02 a8 7e 31 c0 ba 01 00 00 00 <f0> 0f b1 17 85 c0 75 01 c3 55 89 c6 48 89 e5 e8 4e f5 b1 ff 5d
[  487.777854] RIP  [<ffffffff8158aaee>] _raw_spin_lock+0xe/0x30
[  487.777855]  RSP <ffff8808696d79c0>
[  487.777856] CR2: 0000000000000060
[  487.777860] ---[ end trace 672a2cd555e0ebd3 ]---

The cursor code may be entered with file_priv == NULL && handle == NULL.
The problem was introduced by:

"bf89209a drm/mga200g: Hold a proper reference for cursor_set"

which calls drm_gem_object_lookup(dev, file_priv...). Previously this wasn't
a problem because we checked the handle. Move the check early in the function
can fix the problem.
Signed-off-by: NRui Wang <rui.y.wang@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Change-Id: Id6514f2fb6e002437fdbe99353d5d35f4ac736c7
Signed-off-by: NChunming Zhou <David1.Zhou@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>

Change-Id: Ifbb0c06680494bfa04d0be5e5941d31ae2e5ef28
Signed-off-by: NChunming Zhou <David1.Zhou@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>

Change-Id: I62b892a22af37b32e6b4aefca80a25cf45426ed2
Signed-off-by: NChunming Zhou <David1.Zhou@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>

We don't need the last VM use any more, keep the owner directly.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChunming Zhou <davdi1.zhou@amd.com>

It's not a good idea to duplicate that code.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChunming Zhou <davdi1.zhou@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>

Fix the indentation and move the VM functions to the structures.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChunming Zhou <davdi1.zhou@amd.com>
Reviewed-by: NJunwei Zhang <Jerry.Zhang@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>

Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChunming Zhou <davdi1.zhou@amd.com>
Reviewed-by: NJunwei Zhang <Jerry.Zhang@amd.com>

Unify the two code path again, cause they do pretty much the same thing.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChunming Zhou <davdi1.zhou@amd.com>
Reviewed-by: NJunwei Zhang <Jerry.Zhang@amd.com>

Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChunming Zhou <david1.zhou@amd.com>

When diagnosing a unrelated bug for someone on irc, it would seem the hardware can
be brought up by the BIOS with the embedded displayport using the SPLL for spread spectrum.

Right now this is not handled well in i915, and it calculates the crtc needs to
be reprogrammed on the first modeset without SSC, but  the SPLL itself was kept
active. Fix this by exposing SPLL as a shared pll that will not be returned
by intel_get_shared_dpll; you have to know it exists to use it.

Changes since v1:
- Create a separate dpll_hw_state.spll for spll, and use
  separate pll functions for spll.
Tested-by: NEmil Renner Berthing <kernel@esmil.dk>
Tested-by: NGabriel Feceoru <gabriel.feceoru@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447681332-6318-1-git-send-email-maarten.lankhorst@linux.intel.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

With gen < 9 we have had always 50Mhz units as our hw
ratio. With gen >= 9 the hw ratio changed to 16.667Mhz (50/3).
The result was that our gpu frequency tracing started to output
values 3 times larger than expected due to hardcoded scaling
value. Fix this by using  Use intel_gpu_freq() when generating Mhz
value from ratio for 'intel_gpu_freq_change' trace event.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92591
Cc: stable@vger.kernel.org # v4.3+
Reported-by: NEero Tamminen <eero.t.tamminen@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447776866-29384-1-git-send-email-mika.kuoppala@intel.com

We would scan out the memory around them if an upscale was attempted,
and would just scan out incorrectly for downscaling.
Signed-off-by: NEric Anholt <eric@anholt.net>

Caught by the kbuild test robot.

v2: Fix the +i I dropped in the first version.
Signed-off-by: NEric Anholt <eric@anholt.net>

vc4_plane_init() returns an ERR_PTR on error, it doesn't return NULL.
This was obviously intended because the next lines call
PTR_ERR(primary_plane) already.

Fixes: c8b75bca ('Eric Anholt <eric@anholt.net>')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

Connector cannot be null because it is a list entry, ie accessed at an
offset from the positions of the list structure pointers themselves.

Generated by: scripts/coccinelle/iterators/itnull.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NEric Anholt <eric@anholt.net>

drivers/gpu/drm/vc4/vc4_drv.c:248:3-8: No need to set .owner here. The core will do it.

 Remove .owner field if calls are used which set it automatically

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NEric Anholt <eric@anholt.net>

Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NEric Anholt <eric@anholt.net>

We try to convert the old way of of specifying fb tiling (obj->tiling)
into the new fb modifiers. We store the result in the passed in mode_cmd
structure. But that structure comes directly from the addfb2 ioctl, and
gets copied back out to userspace, which means we're clobbering the
modifiers that the user provided (all 0 since the DRM_MODE_FB_MODIFIERS
flag wasn't even set by the user). Hence if the user reuses the struct
for another addfb2, the ioctl will be rejected since it's now asking for
some modifiers w/o the flag set.

Fix the problem by making a copy of the user provided structure. We can
play any games we want with the copy.

IGT-Version: 1.12-git (x86_64) (Linux: 4.4.0-rc1-stereo+ x86_64)
...
Subtest basic-X-tiled: SUCCESS (0.001s)
Test assertion failure function pitch_tests, file kms_addfb_basic.c:167:
Failed assertion: drmIoctl(fd, DRM_IOCTL_MODE_ADDFB2, &f) == 0
Last errno: 22, Invalid argument
Stack trace:
  #0 [__igt_fail_assert+0x101]
  #1 [pitch_tests+0x619]
  #2 [__real_main426+0x2f]
  #3 [main+0x23]
  #4 [__libc_start_main+0xf0]
  #5 [_start+0x29]
  #6 [<unknown>+0x29]
  Subtest framebuffer-vs-set-tiling failed.
  **** DEBUG ****
  Test assertion failure function pitch_tests, file kms_addfb_basic.c:167:
  Failed assertion: drmIoctl(fd, DRM_IOCTL_MODE_ADDFB2, &f) == 0
  Last errno: 22, Invalid argument
  ****  END  ****
  Subtest framebuffer-vs-set-tiling: FAIL (0.003s)
  ...

IGT-Version: 1.12-git (x86_64) (Linux: 4.4.0-rc1-stereo+ x86_64)
Subtest framebuffer-vs-set-tiling: SUCCESS (0.000s)

Cc: stable@vger.kernel.org # v4.1+
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 2a80eada ("drm/i915: Add fb format modifier support")
Testcase: igt/kms_addfb_basic/clobbered-modifier
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447261890-3960-1-git-send-email-ville.syrjala@linux.intel.com

Properly double the hdisplay/vdisplay timings that we use as the primary
plane size with stereo doubled modes. Otherwise the modeset gets
rejected on machines where the primary plane must be fullscreen, and on
the rest only the first eye would get a visible plane.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org #v3.19+
Fixes: 042652ed ("drm/atomic-helper: implementatations for legacy interfaces")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447686157-29607-1-git-send-email-ville.syrjala@linux.intel.com
Testcase: igt/kms_3d
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

If an atomic update fails intel_crtc->atomic may have have some values left
from the last atomic check. One example is atomic->wait_for_vblank,
which results in spurious errors in kms_flip.

[ 1551.892708] ------------[ cut here ]------------
[ 1551.892721] WARNING: CPU: 3 PID: 4179 at ../drivers/gpu/drm/drm_irq.c:1199 drm_wait_one_vblank+0x197/0x1a0 [drm]()
[ 1551.892722] vblank not available on crtc 2, ret=-22
[ 1551.892751] Modules linked in: snd_hda_intel i915 drm_kms_helper drm
intel_gtt i2c_algo_bit cfbfillrect syscopyarea cfbimgblt sysfillrect
sysimgblt fb_sys_fops cfbcopyarea agpgart cfg80211 binfmt_misc
snd_hda_codec_hdmi intel_rapl iosf_mbi x86_pkg_temp_thermal coretemp
kvm_intel snd_hda_codec_realtek kvm snd_hda_codec_generic iTCO_wdt
aesni_intel aes_x86_64 glue_helper lrw snd_hda_codec gf128mul
ablk_helper cryptd snd_hwdep psmouse snd_hda_core pcspkr snd_pcm
snd_timer snd lpc_ich i2c_i801 mfd_core soundcore wmi evdev [last
unloaded: drm]
[ 1551.892753] CPU: 3 PID: 4179 Comm: kms_pipe_crc_ba Tainted: G     U  W       4.3.0-reg+ #6
[ 1551.892754] Hardware name:                  /DZ77BH-55K, BIOS BHZ7710H.86A.0100.2013.0517.0942 05/17/2013
[ 1551.892758]  ffffffffa03128d8 ffff8800cec73890 ffffffff812c0f3c ffff8800cec738d8
[ 1551.892760]  ffff8800cec738c8 ffffffff8104ff36 ffff880116ae2290 0000000000000002
[ 1551.892762]  ffff8800d39fcda0 ffff8800d038b4d0 ffff8800d42b5550 ffff8800cec73928
[ 1551.892763] Call Trace:
[ 1551.892768]  [<ffffffff812c0f3c>] dump_stack+0x4e/0x82
[ 1551.892771]  [<ffffffff8104ff36>] warn_slowpath_common+0x86/0xc0
[ 1551.892773]  [<ffffffff8104ffbc>] warn_slowpath_fmt+0x4c/0x50
[ 1551.892781]  [<ffffffffa02e6708>] ? drm_vblank_get+0x78/0xd0 [drm]
[ 1551.892787]  [<ffffffffa02e6d47>] drm_wait_one_vblank+0x197/0x1a0 [drm]
[ 1551.892813]  [<ffffffffa03d052f>] intel_post_plane_update+0xef/0x120 [i915]
[ 1551.892832]  [<ffffffffa03d11d2>] intel_atomic_commit+0x4c2/0x1600 [i915]
[ 1551.892862]  [<ffffffffa02ff0c7>] ? drm_atomic_check_only+0x147/0x5e0 [drm]
[ 1551.892872]  [<ffffffffa02feeb7>] ? drm_atomic_add_affected_connectors+0x27/0xf0 [drm]
[ 1551.892881]  [<ffffffffa02ff597>] drm_atomic_commit+0x37/0x60 [drm]
[ 1551.892887]  [<ffffffffa034301a>] restore_fbdev_mode+0x28a/0x2c0 [drm_kms_helper]
[ 1551.892895]  [<ffffffffa0345253>] drm_fb_helper_restore_fbdev_mode_unlocked+0x33/0x80 [drm_kms_helper]
[ 1551.892900]  [<ffffffffa03452cd>] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper]
[ 1551.892920]  [<ffffffffa03e7a9a>] intel_fbdev_set_par+0x1a/0x60 [i915]
[ 1551.892923]  [<ffffffff8131a5a7>] fb_set_var+0x1a7/0x3f0
[ 1551.892927]  [<ffffffff8109732f>] ? trace_hardirqs_on_caller+0x12f/0x1c0
[ 1551.892931]  [<ffffffff81314f32>] fbcon_blank+0x212/0x2f0
[ 1551.892935]  [<ffffffff81373f4a>] do_unblank_screen+0xba/0x1d0
[ 1551.892937]  [<ffffffff8136b725>] vt_ioctl+0x13d5/0x1450
[ 1551.892940]  [<ffffffff8107cdd1>] ? preempt_count_sub+0x41/0x50
[ 1551.892943]  [<ffffffff8135d8a3>] tty_ioctl+0x423/0xe30
[ 1551.892947]  [<ffffffff8119f721>] do_vfs_ioctl+0x301/0x560
[ 1551.892949]  [<ffffffff8119b1e3>] ? putname+0x53/0x60
[ 1551.892952]  [<ffffffff811ab376>] ? __fget_light+0x66/0x90
[ 1551.892955]  [<ffffffff8119f9f9>] SyS_ioctl+0x79/0x90
[ 1551.892958]  [<ffffffff81552e97>] entry_SYSCALL_64_fastpath+0x12/0x6f
[ 1551.892961] ---[ end trace 3e764d4b6628c91c ]---

Testcase: kms_flip
Reported-and-tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org #v4.3
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Stone <daniels@collabora.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/5649C2BA.6080300@mblankhorst.nl

Don't touch plane->old_fb/fb without having the right locks held.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-6-git-send-email-maarten.lankhorst@ubuntu.com

Don't touch plane->old_fb/fb without having the right locks held.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-5-git-send-email-maarten.lankhorst@ubuntu.com

This is useful for all the boilerplate code about cleaning old_fb.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447237751-9663-4-git-send-email-maarten.lankhorst@ubuntu.com