It's going away.
v2: Try harder to find them all.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180503093107.25955-1-daniel.vetter@ffwll.ch
In the func drm_atomic_set_crtc_for_plane, with the current code,
if crtc of the plane_state and crtc passed as argument to the func
are same, entire func will executed in vein.
It will get state of crtc and clear and set the bits in plane_mask.
All these steps are not required for same old crtc.
Ideally, we should do nothing in this case, this patch handles the same,
and causes the program to return without doing anything in such scenario.
Signed-off-by: Satendra Singh Thakur <satendra.t@samsung.com>
Cc: Madhur Verma <madhur.verma@samsung.com>
Cc: Hemanshu Srivastava <hemanshu.s@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1525326572-25854-1-git-send-email-satendra.t@samsung.com
I shouldn't have pushed this, CI was right - I failed to remove the
BUG_ON(!ops->wait);
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
dma_fence_default_wait is the default now, same for the trivial
enable_signaling implementation.
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20180427061724.28497-8-daniel.vetter@ffwll.ch
When this was introduced in
commit a519435a96
Author: Christian König <christian.koenig@amd.com>
Date: Tue Oct 20 16:34:16 2015 +0200
dma-buf/fence: add fence_wait_any_timeout function v2
there was a restriction added that this only works if the dma-fence
uses the dma_fence_default_wait hook. Which works for amdgpu, which is
the only caller. Well, until you share some buffers with e.g. i915,
then you get an -EINVAL.
But there's really no reason for this, because all drivers must
support callbacks. The special ->wait hook is only as an optimization;
if the driver needs to create a worker thread for an active callback,
then it can avoid to do that if it knows that there's a process
context available already. So ->wait is just an optimization, just
using the logic in dma_fence_default_wait() should work for all
drivers.
Let's remove this restriction.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180427061724.28497-5-daniel.vetter@ffwll.ch
Noticed while I was typing docs. Entirely unused.
v2: Remove reference in @timeline_value_str too. While at it clarify
why timeline_value_str has a fence parameter - we don't have an
explicit timeline structure unfortunately.
Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: Christian König <christian.koenig@amd.com> (v1)
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: Christian König <christian.koenig@amd.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502082359.30345-1-daniel.vetter@ffwll.ch
Control nodes are no more!
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180420065159.4531-3-daniel.vetter@ffwll.ch
We've disabled control nodes in
commit 8a357d1004
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Fri Oct 28 10:10:50 2016 +0200
drm: Nerf DRM_CONTROL nodes
and there was only a minor uapi break that we've paper over with
commit 6449b088dd
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Fri Dec 9 14:56:56 2016 +0100
drm: Add fake controlD* symlinks for backwards compat
Since then Keith has also added real control nodes with a
proper&useable uapi in the form of drm leases.
It's time to remove the control node leftovers.
Cc: Keith Packard <keithp@keithp.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20180420065159.4531-1-daniel.vetter@ffwll.ch
An overeager sed has corrupted the drm_rect_rotation_inv()
documentation. Fix it up.
Looks like it wasn't entirely correct before the sed fail
either. We were missing _rect_ from the function names, which
also explains why the sed hit these by accident.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180426141631.15798-1-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The Versatile Express has 8 MB of dedicated video RAM (VRAM)
on the motherboard, which is what we should be using for the
PL111 if available. On this platform, the memory backplane
is constructed so that only this memory will work properly
with the CLCD on the motherboard, using any other memory
area just gives random snow on the display.
The CA9 Versatile Express also has a PL111 instance on its
core tile that can address all memory, and this does not
have the restriction.
The memory is assigned to the device using the memory-region
device tree property and a "shared-dma-pool" reserved
memory pool like this:
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
vram: vram@48000000 {
compatible = "shared-dma-pool";
reg = <0x48000000 0x00800000>;
no-map;
};
};
clcd@1f000 {
compatible = "arm,pl111", "arm,primecell";
(...)
memory-region = <&vram>;
}·;
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Mali DP Maintainers <malidp@foss.arm.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502134719.8388-2-linus.walleij@linaro.org
The Versatile Express uses a special configuration controller
deeply embedded in the system motherboard FPGA to multiplex the
two to three (!) display controller instances out to the single
SiI9022 bridge.
Set up an extra file with the logic to probe to the FPGA mux
register on the system controller bus, then parse the device
tree to see if there is a CLCD or HDLCD instance on the core
tile (also known as the daughterboard) by looking in the
root of the device tree for compatible nodes.
- If there is a HDLCD on the core tile, and there is a driver
for it, we exit probe and deactivate the motherboard CLCD.
We do not touch the DVI mux in this case, to make sure we
don't break HDLCD.
- If there is a CLCD on both the motherboard and the core tile
(only the CA9 has this) the core tile CLCD takes precedence
and get muxed to the DVI connector.
- Only if there is no working graphics on the core tile, the
motherboard CLCD is probed and muxed to the DVI connector.
Core tile graphics should always take precedence as it can
address all memory and is also faster, however the motherboard
CLCD is good to have around for diagnostics and testing.
It is possible to test the motherboard CLCD by setting the
status = "disabled" property on the core tile CLCD or
HDLCD.
Scale down the Versatile Express to 16BPP so we can support a
1024x768 display despite the bus bandwidth restrictions on this
platform. (The motherboard CLCD supports slightly lower
resolution.)
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Acked-by: Eric Anholt <eric@anholt.net>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502134719.8388-1-linus.walleij@linaro.org
- Switch to inline member docs for dma_fence_ops.
- Mild polish all around.
- hyperlink all the things!
v2: - Remove the various [in] annotations, they seem really uncommon
in kerneldoc and look funny.
v3: Linebreak the "Returns" part of the @fill_driver_data kerneldoc
(Eric).
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180427061724.28497-2-daniel.vetter@ffwll.ch
Blending win0 with the background color doesn't seem to work
correctly. We only get the background color, no matter the contents of
the win0 framebuffer. However, blending pre-multiplied color with the
default opaque black default background color is a no-op, so we can
just disable blending to get the correct result.
Signed-off-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180418173152.93246-1-hoegsberg@chromium.org
Allow specifying a syncobj on render job submission where we store the
fence for the job. This gives userland flexible access to the fence.
v2: Use 0 as invalid syncobj to drop flag (Eric)
Don't reintroduce the padding (Eric)
Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1524607427-12876-3-git-send-email-stschake@gmail.com
Allow userland to specify a syncobj that is waited on before a render job
starts processing.
v2: Use 0 as invalid syncobj to drop flag (Eric)
Drop extra newline (Eric)
Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1524607427-12876-2-git-send-email-stschake@gmail.com
It turns out that I had just mistaken what type of write the register
writes were supposed to be, using DCS instead of generic long writes.
Switching to transactions instead of using the atmel as a bridge also
seems to resolve the sparkling pixels problem I've had.
Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 2f733d6194 ("drm/panel: Add support for the Raspberry Pi 7" Touchscreen.")
Link: https://patchwork.freedesktop.org/patch/msgid/20171031193258.17373-2-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Sparse complains with following warning:
drivers/gpu/drm/vc4/vc4_v3d.c:222:1: warning: symbol
'vc4_allocate_bin_bo' was not declared. Should it be static?
Make vc4_allocate_bin static as it is not used outside of
vc4_v3d.c.
Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180425070953.17933-1-vthakkar1994@gmail.com
The PiTFT (ili9340) has a hardware reset circuit that resets only
on power-on and not on each reboot through a gpio like the
rpi-display does. As a result, we need to always apply the
rotation value regardless of the display "on/off" state.
Moved the rotation setting code below out_enable:.
Signed-off-by: Tom Callaway <tcallawa@redhat.com>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423161639.14420-1-tcallawa@redhat.com
No functional changes in this patch.
The SDP Header is a generic header for secondary data packets for
both eDP and DP so call it dp_sdp_header. This header gets used for
different SDP types already defined.
Also header bytes 2 and 3 are secondary data packet specific header bytes.
So change the comment to indicate the same.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1524770868-16869-1-git-send-email-manasi.d.navare@intel.com
Add mode_valid() function to filter modes according to available
pll clock values and "preferred" modes. It is particularly
useful for hdmi modes that require precise pixel clocks.
Note that "preferred" modes are always accepted:
- this is important for panels because panel clock tolerances are
bigger than hdmi ones and there is no reason to not accept them
(the fps may vary a little but it is not a problem).
- the hdmi preferred mode will be accepted too, but userland will
be able to use others hdmi "valid" modes if necessary.
Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Yannick Fertré <yannick.fertre@st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180417114026.8709-1-philippe.cornu@st.com
When a driver related to one of the endpoints is deferred
due to probe dependencies (i2c, spi...) but the other one
is ready, ltdc probe continues and the deferred driver
will never be probed again.
The fix consists in waiting for all deferred endpoints before
continuing the ltdc probe.
Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Yannick Fertré <yannick.fertre@st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180417113441.8214-1-philippe.cornu@st.com
These days drm core checks function pointers everywhere before calling
them. So we can drop a bunch of dummy functions now.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180420071904.24276-5-kraxel@redhat.com
The encoder callbacks are only called in case the video mode changes.
So any layout changes without mode changes will go unnoticed.
Add qxl_crtc_update_monitors_config(), based on the old
qxl_write_monitors_config_for_encoder() function. Hook it into the
enable, disable and flush atomic crtc callbacks. Remove monitors_config
updates from all other places.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1544322
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180420071904.24276-4-kraxel@redhat.com
qxl_io_log() sends messages over to the host (qemu) for logging.
Remove the function and all callers, we can just use standard
DRM_DEBUG calls (and if needed a serial console).
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20180420071904.24276-2-kraxel@redhat.com
The "adjusted_mode" clock value (ie the real pixel clock) is more
accurate than "mode" clock value (ie the panel/bridge requested
clock value). It offers a better preciseness for timing
computations and allows to reduce the extra dsi bandwidth in
burst mode (from ~20% to ~10-12%, hw platform dependent).
Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Yannick Fertré <yannick.fertre@st.com>
Tested-by: Yannick Fertré <yannick.fertre@st.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180125155504.8611-1-philippe.cornu@st.com
Bunch of ideas from Eric and me on what we could do to make gem gpu
rendering drivers a notch simpler to type.
v2: Fix typo (Eric).
Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180425111742.5872-1-daniel.vetter@ffwll.ch
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131522.2460-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131515.2360-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method, psb_intel_lvds_mode_valid(), uses an 'int' for it.
Fix this by using 'enum drm_mode_status' for psb_intel_lvds_mode_valid().
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131458.2060-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131455.2011-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131453.1961-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131445.1861-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131520.2409-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131508.2210-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131504.2159-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131450.1910-1-luc.vanoostenryck@gmail.com
The method struct drm_connector_helper_funcs::mode_valid is defined
as returning an 'enum drm_mode_status' but the driver implementation
for this method uses an 'int' for it.
Fix this by using 'enum drm_mode_status' in the driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424131443.1810-1-luc.vanoostenryck@gmail.com
The ADV7511 has four 256-byte maps that can be accessed via the main I2C
ports. Each map has it own I2C address and acts as a standard slave
device on the I2C bus.
Allow a device tree node to override the default addresses so that
address conflicts with other devices on the same bus may be resolved at
the board description level.
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1518544137-2742-6-git-send-email-kbingham@kernel.org
