If there's no need to change it, it should be const. There's more to be
done, but start off with changes that make follow-up work easier. No
functional changes.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/41722f92ef81cd6adf65f936fcc5301418e1f94b.1617024940.git.jani.nikula@intel.com

Since the encoders have been devm-allocated, they will be freed way
before drm_mode_config_cleanup() is called. To avoid use-after-free
conditions, we then must ensure that drm_encoder_cleanup() is called
before the encoders are freed.

v2: Use the new __drmm_simple_encoder_alloc() function

v3: Use the new drmm_plain_simple_encoder_alloc() macro

v4: Use drmm_plain_encoder_alloc() macro

Fixes: c369cb27

 ("drm/ingenic: Support multiple panels/bridges")
Cc: <stable@vger.kernel.org> # 5.8+
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210327115742.18986-4-paul@crapouillou.net

This performs the same operation as drmm_encoder_alloc(), but
only allocates and returns a struct drm_encoder instance.

v4: Rename macro drmm_plain_encoder_alloc() and move to
    <drm/drm_encoder.h>. Since it's not "simple" anymore it
    will now take funcs/name arguments as well.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210327115742.18986-3-paul@crapouillou.net

If we don't call drm_connector_cleanup() manually in
panel_bridge_detach(), the connector will be cleaned up with the other
DRM objects in the call to drm_mode_config_cleanup(). However, since our
drm_connector is devm-allocated, by the time drm_mode_config_cleanup()
will be called, our connector will be long gone. Therefore, the
connector must be cleaned up when the bridge is detached to avoid
use-after-free conditions.

v2: Cleanup connector only if it was created

v3: Add FIXME

v4: (Use connector->dev) directly in if() block

Fixes: 13dfc054

 ("drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge.")
Cc: <stable@vger.kernel.org> # 4.12+
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210327115742.18986-2-paul@crapouillou.net

The shrinker based approach still has some flaws. Especially that we need
temporary pages to free up the pages allocated to the driver is problematic
in a shrinker.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324134845.2338-1-christian.koenig@amd.com

[why]
MST topology print was missing fec logging and pdt printed
as an int wasn't clear. vcpi and payload info was printed as an
arbitrary series of ints which requires user to know the ordering
of the prints, making the logs difficult to use.

[how]
-add fec logging
-add pdt parsing into strings
-format vcpi and payload info into tables with headings
-clean up topology prints
Reviewed-by: Lyude Paul <lyude@redhat.com>

Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Eryk Brol <eryk.brol@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325180614.37060-1-eryk.brol@amd.com

The BO might be NULL in this function, use the bdev directly.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Colin Ian King <colin.king@canonical.com>
Fixes: a1f091f8 ("drm/ttm: switch to per device LRU lock")
Link: https://patchwork.freedesktop.org/patch/msgid/20210325152740.82633-1-christian.koenig@amd.com

Lontium LT8912B is a DSI to HDMI bridge.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Adrien Grassein <adrien.grassein@gmail.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210326121955.1266230-3-adrien.grassein@gmail.com

Lontium LT8912B is a DSI to HDMI bridge.

Signed-off-by: Adrien Grassein <adrien.grassein@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210326121955.1266230-2-adrien.grassein@gmail.com

Fix the following typos:

1. When mentioning a list of functions, the function
drm_atomic_helper_disable_plane is mentioned twice.

2. drop the word 'afterwards':
s/afterwards after that/after that/'

3. drop extra 'the':
s/but do not the support the full/but do not support the full/

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Reviewed-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20210326103216.7918-1-dafna.hirschfeld@collabora.com

struct dss_device has been declared. Remove the duplicate.
And sort these forward declarations alphabetically.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325111028.864628-1-wanjiabing@vivo.com

fixed the following coccicheck:
./drivers/gpu/drm/omapdrm/dss/dsi.c:4329:7-27: ERROR: Threaded IRQ with
no primary handler requested without IRQF_ONESHOT

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Fixes: 4c1b935f

 ("drm/omap: dsi: move TE GPIO handling into core")
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1616492093-68237-1-git-send-email-yang.lee@linux.alibaba.com

An old patch added a 'return' statement after each BUG() in this driver,
which was necessary at the time, but has become redundant after the BUG()
definition was updated to handle this properly.

gcc-11 now warns about one such instance, where the 'return' statement
was incorrectly indented:

drivers/gpu/drm/omapdrm/dss/dispc.c: In function ‘pixinc’:
drivers/gpu/drm/omapdrm/dss/dispc.c:2093:9: error: this ‘else’ clause does not guard... [-Werror=misleading-indentation]
 2093 |         else
      |         ^~~~
drivers/gpu/drm/omapdrm/dss/dispc.c:2095:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘else’
 2095 |                 return 0;
      |                 ^~~~~~

Address this by removing the return again and changing the BUG()
to be unconditional to make this more intuitive.

Fixes: c6eee968

 ("OMAPDSS: remove compiler warnings when CONFIG_BUG=n")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322164203.827324-1-arnd@kernel.org

ICN6211 is MIPI-DSI to RGB Converter bridge from Chipone.

It has a flexible configuration of MIPI DSI signal input and
produce RGB565, RGB666, RGB888 output format.

Add bridge driver for it.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322103328.66442-2-jagan@amarulasolutions.com

ICN6211 is MIPI-DSI to RGB Converter bridge from Chipone.

It has a flexible configuration of MIPI DSI signal input and
produces RGB565, RGB666, RGB888 output format.

Add dt-bingings for it.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322103328.66442-1-jagan@amarulasolutions.com

Fix the following coccicheck warning:

drivers/gpu/drm/bridge/lontium-lt9611uxc.c:858:8-16: WARNING: use
scnprintf or sprintf.

Reported-by: Abaci <Robot&lt;abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1612689000-64577-1-git-send-email-jiapeng.chong@linux.alibaba.com

4k requires two dsi pipes, so don't report MODE_OK when only a
single pipe is configured. But rather report MODE_PANEL to
signal that requirements of the panel are not being met.

Reported-by: Peter Collingbourne <pcc@google.com>
Suggested-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Anibal Limon <anibal.limon@linaro.org>
Tested-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201217140933.1133969-1-robert.foss@linaro.org

Add myself as co-maintainer of DRM Bridge Drivers. Repository
commit access has already been granted.

https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/338



Signed-off-by: Robert Foss <robert.foss@linaro.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Jernej Škrabec <jernej.skrabec@siol.net>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325145154.1433060-1-robert.foss@linaro.org

vkms_vblank_simulate() uses WARN_ON for timing-dependent condition
(timer overrun). This is a mis-use of WARN_ON, WARN_ON must be used
to denote kernel bugs. Use pr_warn() instead.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by:  <syzbot+4fc21a003c8332eb0bdd@syzkaller.appspotmail.com>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Melissa Wen <melissa.srw@gmail.com>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Melissa Wen <melissa.srw@gmail.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210320132840.1315853-1-dvyukov@google.com

Instead of having a global lock for potentially less contention.

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/424010/

Instead evict round robin from each devices SYSTEM and TT domain.

v2: reorder num_pages access reported by Dan's script
v3: fix rebase fallout, num_pages should be 32bit

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/424009/

Move the iteration of the global lru into the new function
ttm_global_swapout() and use that instead in drivers.

v2: consistently return int
v3: fix build fail

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/424008/

The warning message did not printed the LCD pixel clock rate but the LCD
clock divisor input rate. As a consequence, the required and real pixel
clock rates are now passed to the tilcdc_pclk_diff().

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322213337.26667-4-dariobin@libero.it

The tilcdc_pclk_diff() compares the requested pixel clock rate to the
real one, so passing it clk_rate instead of clk_rate / clkdiv caused
it to fail even if the clk_rate was properly set. Adding the
real_pclk_rate variable makes the code more readable.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322213337.26667-3-dariobin@libero.it

The req_rate name is a little misleading, so let's rename to pclk_rate
(pixel clock rate).

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322213337.26667-2-dariobin@libero.it

./drivers/gpu/drm/tilcdc/tilcdc_panel.c:402:3-8: No need to set .owner
here. The core will do it.

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

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/1614762267-98454-1-git-send-email-yang.lee@linux.alibaba.com

Commit 977697e2 ("drm/atomic: Pass the full state to planes atomic
disable and update") added the old_state variable instead of what used
to be a parameter, but it also removed the sole user of that variable in
the vop_plane_atomic_update function leading to an usused variable.
Remove it.

Fixes: 977697e2

 ("drm/atomic: Pass the full state to planes atomic disable and update")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210319152920.262035-1-maxime@cerno.tech

Just another drive-by fix I noticed while going through the tree to cleanup
DP aux adapter registration - make sure we unregister the DP AUX dev if
analogix_dp_probe() fails.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-14-lyude@redhat.com

Another drive-by fix I found when fixing DP AUX adapter across the kernel
tree - make sure we don't leak resources (and by proxy-AUX adapters) on
failures in anx6345_bridge_attach() by unrolling on errors.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-13-lyude@redhat.com

Another case of linking an encoder to a connector after the connector's
been registered. The proper place to do this is before connector
registration, so let's fix that.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-12-lyude@redhat.com

Another driver I found that seems to forget to unregister it's DP AUX
device. Let's fix this by adding anx6345_bridge_detach().

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-11-lyude@redhat.com

Just another issue I noticed while correcting usages of
drm_dp_aux_init()/drm_dp_aux_register() around the tree. If any of the
steps in anx78xx_bridge_attach() fail, we end up leaking resources. So,
let's fix that (and fix leaking a DP AUX adapter in the process) by
unrolling on errors.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-10-lyude@redhat.com

Since encoder mappings for connectors are exposed to userspace, we should
be attaching the encoder before exposing the connector to userspace. Just a
drive-by fix for an issue I noticed while fixing up usages of
drm_dp_aux_init()/drm_dp_aux_register() across the tree.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-9-lyude@redhat.com

Surprisingly, this bridge actually registers it's AUX adapter at the
correct time already. Nice job! However, it does forget to actually
unregister the AUX adapter, so let's add a bridge function to handle that.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-8-lyude@redhat.com

Since we're about to add a back-pointer to drm_dev in drm_dp_aux, let's
move the AUX adapter registration to the first point where we know which
DRM device we'll be working with - when the drm_bridge is attached.
Likewise, we unregister the AUX adapter on bridge detachment by adding a
ti_sn_bridge_detach() callback.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-7-lyude@redhat.com

Since this is a bridge, we don't start out with a respective DRM device.
Likewise this means we don't have a connector, which also means that we
should be following drm_dp_aux_register()'s documentation advice and not
call drm_dp_aux_register() until we have a matching connector. Instead,
call drm_dp_aux_init() in tc_probe() and wait until tc_bridge_attach() to
register our AUX channel. We also add tc_bridge_detach() to handle
unregistering the AUX adapter once the bridge has been disconnected.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-5-lyude@redhat.com

Fix the following coccicheck warning:
drivers/gpu/drm/drm_sysfs.c:172:8-16: WARNING: use scnprintf or sprintf
drivers/gpu/drm/drm_sysfs.c:185:8-16: WARNING: use scnprintf or sprintf
drivers/gpu/drm/drm_sysfs.c:159:8-16: WARNING: use scnprintf or sprintf

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1616375978-12151-1-git-send-email-tiantao6@hisilicon.com

drivers/gpu/drm/gud/gud_connector.c:658:2-3: Unneeded semicolon
drivers/gpu/drm/gud/gud_connector.c:186:2-3: Unneeded semicolon
drivers/gpu/drm/gud/gud_drv.c:511:3-4: Unneeded semicolon
drivers/gpu/drm/gud/gud_pipe.c:127:4-5: Unneeded semicolon

 Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Fixes: 40e1a70b

 ("drm: Add GUD USB Display driver")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
[fix subject and squash 3 per file patches]
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322174434.58849-2-noralf@tronnes.org

drivers/gpu/drm/gud/gud_connector.c:710:37-43: ERROR: application of sizeof to pointer

 sizeof when applied to a pointer typed expression gives the size of
 the pointer

Generated by: scripts/coccinelle/misc/noderef.cocci

Fixes: 40e1a70b

 ("drm: Add GUD USB Display driver")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
[fix subject]
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322174434.58849-1-noralf@tronnes.org

Building with W=1 shows a few warnings for an empty macro:

drivers/gpu/drm/qxl/qxl_drv.c: In function 'qxl_pci_probe':
drivers/gpu/drm/qxl/qxl_drv.c:131:50: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  131 |                 vga_put(pdev, VGA_RSRC_LEGACY_IO);
      |                                                  ^
drivers/gpu/drm/qxl/qxl_drv.c: In function 'qxl_pci_remove':
drivers/gpu/drm/qxl/qxl_drv.c:159:50: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  159 |                 vga_put(pdev, VGA_RSRC_LEGACY_IO);

Change this to an inline function to make it more robust and avoid
the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322105307.1291840-2-arnd@kernel.org