In some cases CRTCs are active but are not able to generating events, at
least not at every frame at it's expected to.
This is typically the case when the CRTC is feeding a writeback connector
that has no job queued. In this situation the CRTC is usually stopped
until a new job is queued, and this can lead to timeouts when part of
the pipeline is updated but no new jobs are queued to the active
writeback connector.

In order to solve that, we add a ->no_vblank flag to drm_crtc_state
and ask the CRTC drivers to set it to true when they know they're not
able to generate VBLANK events. The core drm_atomic_helper_fake_vblank()
helper can then be used to fake VBLANKs at commit time.
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: NLiviu Dudau <liviu.dudau@arm.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180703075022.15138-6-boris.brezillon@bootlin.com

Move the plane clip rectangle handling into
drm_atomic_helper_check_plane_state(). Drivers no longer
have to worry about such mundane details.

v2: Convert armada, rcar, and sun4i as well
v3: Resolve simple_kms_helper conflict

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: CK Hu <ck.hu@mediatek.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Suggested-by: NDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org> #msm
Link: https://patchwork.freedesktop.org/patch/msgid/20180123170857.13818-5-ville.syrjala@linux.intel.com
Acked-by: Liviu Dudau <liviu.dudau@arm.com> #hdlcd,malidp
Acked-by: Philipp Zabel <p.zabel@pengutronix.de> #imx,mtk
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com> #vmwgfx
Acked-by: Neil Armstrong <narmstrong@baylibre.com> #meson
Acked-by: Shawn Guo <shawnguo@kernel.org> #zte

drm_plane_helper_check_update() isn't a transitional helper, so let's
rename it to drm_atomic_helper_check_plane_state() and move it into
drm_atomic_helper.c.

v2: Fix the WARNs about plane_state->crtc matching crtc_state->crtc

Cc: Daniel Vetter <daniel@ffwll.ch>
Suggested-by: NDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171101201619.6175-1-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's dead code, the core handles all this directly now.

The only special case is nouveau and tda988x which used one function
for both legacy modeset code and -nv50 atomic world instead of 2
vtables. But amounts to exactly the same.

v2: Rebase over the panel/brideg refactorings in stm/ltdc.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Peter Senna Tschudin <peter.senna@collabora.com>
Cc: Martin Donnelly <martin.donnelly@ge.com>
Cc: Martyn Welch <martyn.welch@collabora.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
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>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Alison Wang <alison.wang@freescale.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: CK Hu <ck.hu@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Mark Yao <mark.yao@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Jeffy Chen <jeffy.chen@rock-chips.com>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Yakir Yang <kuankuan.y@gmail.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Cc: Romain Perier <romain.perier@collabora.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: Xinliang Liu <z.liuxinliang@hisilicon.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Hai Li <hali@codeaurora.org>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: nouveau@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-tegra@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: zain wang <wzz@rock-chips.com>
Cc: Baoyou Xie <baoyou.xie@linaro.org>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170725080122.20548-8-daniel.vetter@ffwll.chAcked-by: NNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: NNeil Armstrong <narmstrong@baylibre.com>
Acked-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NArchit Taneja <architt@codeaurora.org>
Tested-by: Philippe Cornu <philippe.cornu@st.com> (on stm)
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NShawn Guo <shawnguo@kernel.org>
Acked-by: NShawn Guo <shawnguo@kernel.org>
Acked-by: NNoralf Trønnes <noralf@tronnes.org>
Acked-by: NVincent Abriou <vincent.abriou@st.com>

It's dead code, the core handles all this directly now. This also
allows us to unexport drm_atomic_helper_connector_set_property.

The only special case is nouveau which used one function for both
pre-nv50 legacy modeset code and post-nv50 atomic world instead of 2
vtables. But amounts to exactly the same.

What is rather strange here is how few drivers set this up, I suspect
the earlier patch to handle properties in the core did end up fixing a
pile of possible issues.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: intel-gfx@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170725080122.20548-7-daniel.vetter@ffwll.chAcked-by: NVincent Abriou <vincent.abriou@st.com>

It's dead code, the core handles all this directly now. This also
allows us to unexport drm_atomic_plane_set_property.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
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>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Eric Engestrom <eric@engestrom.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170725080122.20548-6-daniel.vetter@ffwll.chReviewed-by: NArchit Taneja <architt@codeaurora.org>
Acked-by: NPhilippe Cornu <philippe.cornu@st.com>
Tested-by: NPhilippe Cornu <philippe.cornu@st.com>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Acked-by: NVincent Abriou <vincent.abriou@st.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>

It's dead code because this is now handled in the core.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Eric Engestrom <eric@engestrom.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Sushmita Susheelendra <ssusheel@codeaurora.org>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: intel-gfx@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170725080122.20548-5-daniel.vetter@ffwll.chReviewed-by: NArchit Taneja <architt@codeaurora.org>
Acked-by: NPhilippe Cornu <philippe.cornu@st.com>
Tested-by: NPhilippe Cornu <philippe.cornu@st.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NThomas Hellstrom <thellstrom@vmware.com>

The current drm_atomic_helper_commit_tail helper works only if the CRTC is
accessible, and documents an alternative implementation that is supposed to
be used if that happens.

That implementation is then duplicated by some drivers. Instead of
documenting it, let's implement an helper that all the relevant users can
use directly.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/a8f92dc70048bab746e94dadd1c23200626aff60.1500555652.git-series.maxime.ripard@free-electrons.comSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that all drivers check the return value, convert swap_state to
__must_check. This is done separately to force build warnings if we
missed a driver.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170711143314.2148-12-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want to change swap_state to wait indefinitely, but to do this
swap_state should wait interruptibly. This requires propagating
the error to each driver.

Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170711143314.2148-3-maarten.lankhorst@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
[mlankhorst: Fix typos in swap_state documentation (seanpaul)]
Reviewed-by: Sean Paul <seanpaul@chromium.org>]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make the atomic private object stuff less special by introducing proper
base classes for the object and its state. Drivers can embed these in
their own appropriate objects, after which these things will work
exactly like the plane/crtc/connector states during atomic operations.

v2: Reorder to not depend on drm_dynarray (Daniel)

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v1
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170712155102.26276-3-ville.syrjala@linux.intel.com

In some cases, like cursor updates, it is interesting to update the
plane in an asynchronous fashion to avoid big delays. The current queued
update could be still waiting for a fence to signal and thus block any
subsequent update until its scan out. In cases like this if we update the
cursor synchronously through the atomic API it will cause significant
delays that would even be noticed by the final user.

This patch creates a fast path to jump ahead the current queued state and
do single planes updates without going through all atomic steps in
drm_atomic_helper_commit(). We take this path for legacy cursor updates.

For now only single plane updates are supported, but we plan to support
multiple planes updates and async PageFlips through this interface as well
in the near future.

v6:	- move check code to drm_atomic_helper.c (Daniel Vetter)

v5:
	- improve comments (Eric Anholt)

v4:
	- fix state->crtc NULL check (Archit Taneja)

v3:
	- fix iteration on the wrong crtc state
	- put back code to forbid updates if there is a queued update for
	the same plane (Ville Syrjälä)
	- move size checks back to drivers (Ville Syrjälä)
	- move ASYNC_UPDATE flag addition to its own patch (Ville Syrjälä)

v2:
	- allow updates even if there is a queued update for the same
	plane.
        - fixes on the documentation (Emil Velikov)
        - unconditionally call ->atomic_async_update (Emil Velikov)
        - check for ->atomic_async_update earlier (Daniel Vetter)
        - make ->atomic_async_check() the last step (Daniel Vetter)
        - add ASYNC_UPDATE flag (Eric Anholt)
        - update state in core after ->atomic_async_update (Eric Anholt)
	- update docs (Eric Anholt)

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org> (v5)
Acked-by: Eric Anholt <eric@anholt.net> (v5)
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170630180322.29007-2-gustavo@padovan.org

Add an helper to wait for all page flips of an atomic state to be done.

v2:
- Pimp kerneldoc as discussed with Boris on irc
- Add missing doc for @dev.
- Use old_state for consitency with wait_for_vblanks

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> (v1)
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1496392332-8722-2-git-send-email-boris.brezillon@free-electrons.com

Atomic helpers really want this instead of the hacked-up legacy
backoff trick, which unfortunately prevents drivers from using their
own private drm_modeset_locks.

Aside: There's a few atomic drivers (nv50, vc4, soon vmwgfx) which
don't yet use the new atomic color mgmt/gamma table stuff. Would be
nice if they could switch over and just hook up
drm_atomic_helper_legacy_gamma_set() instead.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NSinclair Yeh <syeh@vmware.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170403083304.9083-13-daniel.vetter@ffwll.ch

Surprisingly a lot of legacy drivers roll their own, for
runtime pm and because vmwgfx.

Also make nouveau's set_config static while at it.

Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-19-daniel.vetter@ffwll.ch

Again just going through the motions, no functional changes in here.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>t
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-12-daniel.vetter@ffwll.ch

Nouveau had a few direct calls to ->disable_plane, I replaced those
with drm_plane_force_disable. Same story for shmob.

Otherwise no code changes.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-5-daniel.vetter@ffwll.ch

Just rolling it out, no code change here.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-3-daniel.vetter@ffwll.ch

The trouble here is that it does multiple atomic commits under one
drm_modeset_lock_all, which breaks the behind-the-scenes acquire
context magic that function pulls off. It's much better to have one
overall atomic commit. That we still have multiple atomic commits
prevents us from adding some pretty useful debug checks to the atomic
machinery.

Hence it is really a bad idea to call the legacy
drm_crtc_force_disable_all() function. There's 2 atomic drivers using
this still, nouveau and tinydrm. To fix this, introduce a new
drm_atomic_helper_shutdown() by extracting the code from i915.

While at it improve kernel-doc and catch future offenders by
sprinkling a WARN_ON into the legacy function. We should probably move
those into the legacy modeset helpers, too ...

v2: Make it compile on arm drivers too (Noralf).

v3: Correct kerneldoc to point at _disable_all().
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NNoralf Trønnes <noralf@tronnes.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Tested-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170321164149.31531-1-daniel.vetter@ffwll.ch

This function becomes a lot simpler when having passed both the old and
new state to it. Looking at all callers, it seems that old_plane_state
is never NULL so the check can be dropped.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1487256430-7625-3-git-send-email-maarten.lankhorst@linux.intel.comReviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>

Add for_each_(old)(new)_(plane,connector,crtc)_in_state iterators to
replace the old for_each_xxx_in_state ones. This is useful for >1 flip
depth and getting rid of all xxx->state dereferences.

This requires extra fixups done when committing a state after
duplicating, which in general isn't valid but is used by suspend/resume.
To handle these, introduce drm_atomic_helper_commit_duplicated_state
which performs those fixups before checking & committing the state.

Changes since v1:
- Remove nonblock parameter for commit_duplicated_state.
Changes since v2:
- Use commit_duplicated_state for i915 load detection.
- Add WARN_ON(old_state != obj->state) before swapping.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1484559464-27107-2-git-send-email-maarten.lankhorst@linux.intel.com

I just learned that &struct_name.member_name works and looks pretty
even. It doesn't (yet) link to the member directly though, which would
be really good for big structures or vfunc tables (where the
per-member kerneldoc tends to be long).

Also some minor drive-by polish where it makes sense, I read a lot
of docs ...

v2: Comments from Gustavo.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Rewiewed-by: NGustavo Padovan <gustavo.padovan@collabora.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170125062657.19270-2-daniel.vetter@ffwll.ch

Allows usage of the new page_flip_target hook for drivers implementing
the atomic path.
Provides default atomic helper for the new hook.

v2:
Update code sharing logic between exsiting and the new flip hooks.
Improve kerneldoc.
Signed-off-by: NAndrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1483735180-4173-1-git-send-email-Andrey.Grodzovsky@amd.com

This function is now completely unused, zap it.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1481204729-9058-6-git-send-email-maarten.lankhorst@linux.intel.com

If userspace is running an synchronously atomic commit and interrupts the
atomic operation during fence_wait() it will hang until the timer expires,
so here we change the wait to be interruptible so it stop immediately when
userspace wants to quit.

Also adds the necessary error checking for fence_wait().

v2: Comment by Daniel Vetter
	- Add error checking for fence_wait()

v3: Rebase on top of new atomic noblocking support

v4: Comment by Maarten Lankhorst
	- remove 'swapped' bitfield as it was duplicating information

v5: Comments by Maarten Lankhorst
	- assign plane->state to plane_state if !intr
	- squash previous patch into this one

v6: Comment by Sean Paul
	- rename intr to pre_swap
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
[seanpaul fixed a couple checkpatch warnings and moved the preswap comment]
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1473707291-14781-1-git-send-email-gustavo@padovan.org

Drivers may set the NO_DISABLE_AFTER_MODESET flag in the 'flags' parameter
of the helper drm_atomic_helper_commit_planes() if the relevant display
controllers(e.g., IPUv3 for imx-drm) require to disable a CRTC's planes
when the CRTC is disabled. The helper would skip the ->atomic_disable
call for a plane if the CRTC of the old plane state needs a modesetting
operation. Of course, the drivers need to disable the planes in their CRTC
disable callbacks since no one else would do that.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1472461923-14364-1-git-send-email-gnuiyl@gmail.com

Currently, the helper drm_atomic_helper_disable_planes_on_crtc() calls
->atomic_disable for all planes _to be_ enabled on a particular CRTC.
This is obviously wrong for those planes which are not scanning out frames
when the helper is called.  Instead, it's sane to disable active planes
of old_crtc_state in the helper.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLiu Ying <gnuiyl@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1472196644-30563-3-git-send-email-gnuiyl@gmail.com

While reviewing docs I spotted that we have a few functions that
really just don't fit into their containing helper library section.
Extract them and shovel them all into a new library for random one-off
aux stuff.

v2: Remove wrongly added files for real.

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/1471034937-651-3-git-send-email-daniel.vetter@ffwll.ch

Documentation for drm_atomic_crtc_for_each_plane() makes reference to
a function called drm_crtc_for_each_pending_plane(). I've guessed that
the actual function name is drm_atomic_crtc_state_for_each_plane() as
that matches best the intent of the comment.
Signed-off-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465571005-3877-1-git-send-email-Liviu.Dudau@arm.com

Design ideas:

- split up the actual commit into different phases, and have
  completions for each of them. This will be useful for the future
  when we want to interleave phases much more aggressively, for e.g.
  queue depth > 1. For not it's just a minimal optimization compared
  to current common nonblocking implementation patterns from drivers,
  which all stall for the entire commit to complete, including vblank
  waits and cleanups.

- Extract a separate atomic_commit_hw hook since that's the part most
  drivers will need to overwrite, hopefully allowing even more shared
  code.

- Enforce EBUSY seamntics by attaching one of the completions to the
  flip_done vblank event. Side benefit of forcing atomic drivers using
  these helpers to implement event handlign at least semi-correct. I'm
  evil that way ;-)

- Ridiculously modular, as usual.

- The main tracking unit for a commit stays struct drm_atomic_state,
  and the ownership rules for that are unchanged. Ownership still
  gets transferred to the driver (and subsequently to the worker) on
  successful commits. What is added is a small, per-crtc, refcounted
  structure to track pending commits called struct drm_crtc_commit.
  No actual state is attached to that though, it's purely for ordering
  and waiting.

- Dependencies are implicitly handled by assuming that any CRTC part
  of &drm_atomic_state is a dependency, and that the current commit
  must wait for any commits to complete on those CRTC. This way
  drivers can easily add more depencies using
  drm_atomic_get_crtc_state(), which is very natural since in most
  case a dependency exists iff there's some bit of state that needs to
  be cross checked.

  Removing depencies is not possible, drivers simply need to be
  careful to not include every CRTC in a commit if that's not
  necessary. Which is a good idea anyway, since that also avoids
  ww_mutex lock contention.

- Queue depth > 1 sees some prep work in this patch by adding a stall
  paramater to drm_atomic_helper_swap_states(). To be able to push
  commits entirely free-standing and in a deeper queue through the
  back-end the driver must not access any obj->state pointers. This
  means we need to track the old state in drm_atomic_state (much
  easier with the consolidated arrays), and pass them all explicitly
  to driver backends (this will be serious amounts of churn).

  Once that's done stall can be set to false in swap_states.

v2: Dont ask for flip_done signalling when the CRTC is off and stays
off: Drivers don't handle events in that case. Instead complete right
away. This way future commits don't need to have special-case logic,
but can keep blocking for the flip_done completion.

v3: Tons of fixes:
- Stall for preceeding commit for real, not the current one by
  accident.
- Add WARN_ON in case drivers don't fire the drm event.
- Don't double-free drm events.

v4: Make legacy cursor not stall.

v5: Extend the helper hook to cover the entire commit tail. Some
drivers need special code for cleanup and vblank waiting, this makes
it a bit more useful. Inspired by the rockchip driver.

v6: Add WARN_ON to catch drivers who forget to send out the
drm event.

v7: Fixup the stalls in swap_state for real!!

v8:
- Fixup trailing whitespace, spotted by Maarten.
- Actually wait for flip_done in cleanup_done, like the comment says
  we should do. Thanks a lot for Tomeu for helping with debugging this
  on.

v9: Now with awesome kerneldoc!

v10: Split out drm_crtc_commit tracking infrastructure.

v:
- Add missing static (Gustavo).
- Split out the sync functions, only do the actual nonblocking
  logic in this patch (Maarten).

Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Tested-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tomeu Vizoso <tomeu.vizoso@gmail.com>
Cc: Daniel Stone <daniels@collabora.com>
Tested-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Testcase: igt/kms_flip/*
Testcase: igt/kms_cursor*
Testcase: igt/kms*plane*
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-10-git-send-email-daniel.vetter@ffwll.ch

To facilitate easier reviewing this is split out from the overall
nonblocking commit rework. It just rolls out the helper functions
and uses them in the main drm_atomic_helper_commit() function
to make it clear where in the flow they're used.

The next patch will actually split drm_atomic_helper_commit() into
2 pieces, with the tail being run asynchronously from a worker.

v2: Improve kerneldocs (Maarten).

v3: Don't convert ERESTARTSYS to EINTR (Maarten). Also don't fail if
the wait succeed in stall_check - we need to convert that case (it
returns the remaining jiffies) to 0 for success.

v4: Switch to long for wait_for_completion_timeout return value
everywhere (Maarten).

v5: Fix miscaped function in kerneldoc (Maarten).
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Tested-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tomeu Vizoso <tomeu.vizoso@gmail.com>
Cc: Daniel Stone <daniels@collabora.com>
Tested-by: NLiviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465398936-22305-1-git-send-email-daniel.vetter@ffwll.ch

- dev is redundant, we have state->atomic
- add stall parameter, which must be set when swapping needs to stall
  for preceeding commits to stop looking at ->state pointers. Currently
  all drivers need this to be, just prep work for a glorious future.

v2: Rebased on top of

commit e7cf0963
Author: Gerd Hoffmann <kraxel@redhat.com>
Date:   Tue May 31 08:50:47 2016 +0200

    virtio-gpu: add atomic_commit function

Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465509992-19284-1-git-send-email-daniel.vetter@ffwll.ch
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-2-git-send-email-daniel.vetter@ffwll.ch

Change return value to int to propagate errors from gamma_set,
and remove start parameter. Updates always use the full size,
and some drivers even ignore the start parameter altogether.

This is needed for atomic drivers, where an atomic commit can
fail with -EINTR or -ENOMEM and should be restarted. This is already
and issue for drm_atomic_helper_legacy_set_gamma, which this patch
fixes up.

Changes since v1:
- Fix compiler warning. (Emil)
- Fix commit message (Daniel)

Cc: Alex Deucher <alexander.deucher@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Mathieu Larouche <mathieu.larouche@matrox.com>
Cc: Thierry Reding <treding@nvidia.com>
Acked-by: NPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Improve commit message a bit more, mention that this fixes
the helper.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/742944bc-9f41-1acb-df4f-0fd4c8a10168@linux.intel.com

... and use it in msm&vc4. Again just want to encapsulate
drm_atomic_state internals a bit.

The const threading is a bit awkward in vc4 since C sucks, but I still
think it's worth to enforce this. Eventually I want to make all the
obj->state pointers const too, but that's a lot more work ...

v2: Provide safe macro to wrap up the unsafe helper better, suggested
by Maarten.

v3: Fixup subject (Maarten) and spelling fixes (Eric Engestrom).

Cc: Eric Anholt <eric@anholt.net>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464877304-4213-1-git-send-email-daniel.vetter@ffwll.ch

It's unused, and really this helper should only look at the state
structure and nothing else. Note that this conflicts with a patch from
Dave that adds refcounting to drm_connectors. It's not yet clear
whether the check Dave adds for connector != NULL is really needed or
the right check.

v2: Fix commmit message (Laurent).

Cc: Dave Airlie <airlied@gmail.com>
Acked-by: NThierry Reding <thierry.reding@gmail.com>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462804451-15318-3-git-send-email-daniel.vetter@ffwll.ch

It's unused, and really this helper should only look at the state
structure and nothing else.

v2: Fix commit message (Laurent).

v3: Rebase onto mtk driver merge.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Mark Yao <mark.yao@rock-chips.com>
Acked-by: NThierry Reding <thierry.reding@gmail.com>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462804451-15318-2-git-send-email-daniel.vetter@ffwll.ch

It's unused, and really this helper should only look at the state
structure and nothing else.

v2: Rebase on top of rockchip changes

v3: Drop unrelated hunk, spotted by Laurent.

v4: Rebase onto mtk driver merge.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Mark Yao <mark.yao@rock-chips.com>
Acked-by: NThierry Reding <thierry.reding@gmail.com>
Acked-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462804451-15318-1-git-send-email-daniel.vetter@ffwll.ch

Add (struct drm_connector_helper_funcs *)->best_encoder callback helper
for connectors that support exactly 1 encoder, statically determined at
driver init time.
Signed-off-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462982962-10530-6-git-send-email-noralf@tronnes.org

This is the first step of renaming async commit to nonblocking commit.
The flag passed by userspace is NONBLOCKING, and async has a different
meaning for page flips, where it means as soon as possible.

Fixing up comments in drm core is done manually, to make sure I didn't
miss anything.

For drivers, the following cocci script is used to rename bool async to bool
nonblock:
@@
identifier I =~ "^async";
identifier func;
@@
func(..., bool
- I
+ nonblock
, ...)
{
<...
- I
+ nonblock
...>
}
@@
identifier func;
type T;
identifier I =~ "^async";
@@
T func(..., bool
- I
+ nonblock
, ...);

Thanks to Tvrtko Ursulin for the cocci script.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461679905-30177-2-git-send-email-maarten.lankhorst@linux.intel.com

Signed-off-by: NRob Clark <robdclark@gmail.com>
Reviewed-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1458342904-23326-3-git-send-email-robdclark@gmail.com