Commit Graph

1015699 Commits

Author SHA1 Message Date
Heiko Stuebner
71f68fe7f1 drm/rockchip: dsi: add ability to work as a phy instead of full dsi
SoCs like the rk3288 and rk3399 have 3 mipi dphys on them. One is TX-
only, one is RX-only and one can be configured to do either TX or RX.

The RX phy is statically connected to the first Image Signal Processor,
the TX phy is statically connected to the first DSI controller and
the TXRX phy is connected to both the second DSI controller as well
as the second ISP.

The RX dphy is controlled externally through registers in the "General
Register Files", while the other two are controlled through the
"Configuration and Test Interface" inside their DSI controller's
io-memory area.

The Rockchip dw-dsi controller already controls these dphys for the
TX case in the driver, but when we want to also allow configuration
for RX to the ISP from the media subsystem we need to expose phy-
functionality instead.

So add a bit of infrastructure to allow the dsi driver to work as a
phy and make sure it can be only one or the other at a time.

Similarly as the dsi-controller will be part of the drm-graph when
active, add an empty component to the drm-graph when in phy-mode
to make the rest of the drm-graph not wait for it.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Tested-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Acked-by: Helen Koike <helen.koike@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210210111020.2476369-4-heiko@sntech.de
2021-07-25 17:19:49 +02:00
Heiko Stuebner
a812413984 dt-bindings: display: rockchip-dsi: add optional #phy-cells property
The Rockchip DSI controller on some SoCs also controls a bidrectional
dphy, which would be connected to an Image Signal Processor as a phy
in the rx configuration.

So allow a #phy-cells property for the dsi controller.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Acked-by: Helen Koike <helen.koike@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210210111020.2476369-3-heiko@sntech.de
2021-07-25 17:05:52 +02:00
Heiko Stuebner
c92ecb4eac drm/rockchip: dsi: add own additional pclk handling
In a followup patch, we'll need to access the pclk ourself to enable some
functionality, so get and store it in the rockchip dw-dsi variant as well.

Clocks are refcounted, so possible cascading enablements are
no problem.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Tested-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Acked-by: Helen Koike <helen.koike@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210210111020.2476369-2-heiko@sntech.de
2021-07-25 17:05:40 +02:00
Geert Uytterhoeven
1f49bf8b6a dt-bindings: display: ssd1307fb: Convert to json-schema
Convert the Solomon SSD1307 Framebuffer Device Tree binding
documentation to json-schema.

Fix the spelling of the "pwms" property.
Document default values.
Make properties with default values not required.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714145122.2530176-1-geert@linux-m68k.org
2021-07-25 14:23:00 +02:00
Geert Uytterhoeven
47956bc86e drm/bridge: nwl-dsi: Avoid potential multiplication overflow on 32-bit
As nwl_dsi.lanes is u32, and NSEC_PER_SEC is 1000000000L, the second
multiplication in

    dsi->lanes * 8 * NSEC_PER_SEC

will overflow on a 32-bit platform.  Fix this by making the constant
unsigned long long, forcing 64-bit arithmetic.

As iMX8 is arm64, this driver is currently used on 64-bit platforms
only, where long is 64-bit, so this cannot happen.  But the issue will
start to happen when the driver is reused for a 32-bit SoC (e.g.
i.MX7ULP), or when code is copied for a new driver.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/ebb82941a86b4e35c4fcfb1ef5a5cfad7c1fceab.1626255956.git.geert+renesas@glider.be
2021-07-25 14:15:18 +02:00
Oleksij Rempel
6474e67eab dt-bindings: display: simple: add some Logic Technologies and Multi-Inno panels
Add Logictechno and Multi-Inno panels:
- Logic Technologies LTTD800x480 L2RT 7" 800x480 TFT Resistive Touch Module
- Logic Technologies LTTD800480070-L6WH-RT 7” 800x480 TFT Resistive Touch Module
- Multi-Inno Technology Co.,Ltd MI1010AIT-1CP 10.1" 1280x800 LVDS IPS Cap Touch Mod.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714045349.10963-2-o.rempel@pengutronix.de
2021-07-25 14:00:47 +02:00
Thomas Zimmermann
1522756c79 drm/shmobile: Convert to Linux IRQ interfaces
Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
don't benefit from using it.

v3:
	* return error if (ret < 0) (Geert)
	* remove duplicate error message (Geert)
v2:
	* handle errors in platform_get_irq() (Geert, Sergei)
	* store IRQ number in struct shmob_drm_device (Laurent)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210720080941.23646-1-tzimmermann@suse.de
2021-07-25 11:01:12 +02:00
Thomas Zimmermann
9200454ca0 drm/st7586: Use framebuffer dma-buf helpers
Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: David Lechner <david@lechnology.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-8-tzimmermann@suse.de
2021-07-23 20:18:14 +02:00
Thomas Zimmermann
baf6c24bac drm/repaper: Use framebuffer dma-buf helpers
Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-7-tzimmermann@suse.de
2021-07-23 20:18:11 +02:00
Thomas Zimmermann
329e2c42f8 drm/gm12u320: Use framebuffer dma-buf helpers
Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-6-tzimmermann@suse.de
2021-07-23 20:18:08 +02:00
Thomas Zimmermann
08b7ef0524 drm/gud: Use framebuffer dma-buf helpers
Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-5-tzimmermann@suse.de
2021-07-23 20:18:04 +02:00
Thomas Zimmermann
08971eea06 drm/mipi-dbi: Use framebuffer dma-buf helpers
Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

There's one left-over reference to the imported attachment that we
keep. GEM BOs with imported attachment are considered uncached and
enables special handling within the drm_fb_swab().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-4-tzimmermann@suse.de
2021-07-23 20:17:59 +02:00
Thomas Zimmermann
ce724470a2 drm/udl: Use framebuffer dma-buf helpers
Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-3-tzimmermann@suse.de
2021-07-23 20:17:42 +02:00
Thomas Zimmermann
37408cd825 drm/gem: Provide drm_gem_fb_{begin,end}_cpu_access() helpers
Implement helpers drm_gem_fb_begin_cpu_access() and _end_cpu_access(),
which call the rsp dma-buf functions for all GEM BOs of the given
framebuffer.

Calls to dma_buf_end_cpu_access() can return an error code on failure,
while drm_gem_fb_end_cpu_access() does not. The latter runs during DRM's
atomic commit or during cleanup. Both cases don't allow for errors, so
leave out the return value.

v2:
	* fix typo in docs (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-2-tzimmermann@suse.de
2021-07-23 20:17:13 +02:00
Thomas Zimmermann
a791cde6d2 drm/hisilicon/hibmc: Remove variable 'priv' from hibmc_unload()
The variable 'priv' got introduced in commit 39a364a19e
("drm/hisilicon/hibmc: Convert to Linux IRQ interfaces") by accident.
It's unused; remove it. Fixes a compiler warning.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 39a364a19e ("drm/hisilicon/hibmc: Convert to Linux IRQ interfaces")
Reviewed-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reported-by: Dave Airlie <airlied@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721131704.10306-1-tzimmermann@suse.de
2021-07-23 20:06:17 +02:00
Normunds Rieksts
90c7c70a0a drm/fourcc: Add modifier definitions for Arm Fixed Rate Compression
Arm Fixed Rate Compression (AFRC) is a proprietary fixed rate image
compression protocol and format.
It is designed to provide guaranteed bandwidth and memory footprint
reductions in graphics and media use-cases.

This patch aims to add modifier definitions for describing
AFRC.

Signed-off-by: Normunds Rieksts <normunds.rieksts@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210701170709.39922-1-normunds.rieksts@arm.com
2021-07-23 16:10:22 +01:00
Maxime Ripard
c18c36dc75
Documentation: gpu: Mention the requirements for new properties
New KMS properties come with a bunch of requirements to avoid each
driver from running their own, inconsistent, set of properties,
eventually leading to issues like property conflicts, inconsistencies
between drivers and semantics, etc.

Let's document what we expect.

Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210720143544.571760-1-maxime@cerno.tech
2021-07-23 13:51:58 +02:00
Chris Morgan
8626e63eee drm/panfrost: devfreq: Don't display error for EPROBE_DEFER
Set a condition for the message of "Couldn't set OPP regulators" to not
display if the error code is EPROBE_DEFER. Note that I used an if
statement to capture the condition instead of the dev_err_probe
function because I didn't want to change the DRM_DEV_ERROR usage.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721214830.25690-1-macroalpha82@gmail.com
2021-07-23 12:06:29 +01:00
Maxime Ripard
474596fc74
dt-bindings: display: simple-bridge: Add corpro,gm7123 compatible
The corpro,gm7123 was in use in a DT but was never properly documented,
let's add it.

Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721140424.725744-12-maxime@cerno.tech
2021-07-22 11:42:54 +02:00
Zheyu Ma
030fadb013 video: fbdev: neofb: add a check against divide error
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'pixclock',
it may cause divide error because of the 'PICOS2KHZ' macro.

Fix this by checking whether 'pixclock' is zero first.

The following log reveals it:

[   53.093806] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[   53.093838] CPU: 3 PID: 11763 Comm: hang Not tainted 5.14.0-rc2-00478-g2734d6c1b1a0 #215
[   53.093859] RIP: 0010:neofb_check_var+0x80/0xe50
[   53.093951] Call Trace:
[   53.093956]  ? neofb_setcolreg+0x2b0/0x2b0
[   53.093968]  fb_set_var+0x2e4/0xeb0
[   53.093977]  ? fb_blank+0x1a0/0x1a0
[   53.093984]  ? lock_acquire+0x1ef/0x530
[   53.093996]  ? lock_release+0x810/0x810
[   53.094005]  ? lock_is_held_type+0x100/0x140
[   53.094016]  ? ___might_sleep+0x1ee/0x2d0
[   53.094028]  ? __mutex_lock+0x620/0x1190
[   53.094036]  ? do_fb_ioctl+0x313/0x700
[   53.094044]  ? mutex_lock_io_nested+0xfa0/0xfa0
[   53.094051]  ? __this_cpu_preempt_check+0x1d/0x30
[   53.094060]  ? _raw_spin_unlock_irqrestore+0x46/0x60
[   53.094069]  ? lockdep_hardirqs_on+0x59/0x100
[   53.094076]  ? _raw_spin_unlock_irqrestore+0x46/0x60
[   53.094085]  ? trace_hardirqs_on+0x6a/0x1c0
[   53.094096]  do_fb_ioctl+0x31e/0x700

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1626871424-27708-1-git-send-email-zheyuma97@gmail.com
2021-07-21 15:02:03 +02:00
Colin Ian King
99279ad8fe video: fbdev: arcfb: remove redundant initialization of variable err
The variable err is being initialized with a value that is never
read, the assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721102608.42694-1-colin.king@canonical.com
2021-07-21 13:09:21 +02:00
Javier Martinez Canillas
8633ef82f1 drivers/firmware: consolidate EFI framebuffer setup for all arches
The register_gop_device() function registers an "efi-framebuffer" platform
device to match against the efifb driver, to have an early framebuffer for
EFI platforms.

But there is already support to do exactly the same by the Generic System
Framebuffers (sysfb) driver. This used to be only for X86 but it has been
moved to drivers/firmware and could be reused by other architectures.

Also, besides supporting registering an "efi-framebuffer", this driver can
register a "simple-framebuffer" allowing to use the siple{fb,drm} drivers
on non-X86 EFI platforms. For example, on aarch64 these drivers can only
be used with DT and doesn't have code to register a "simple-frambuffer"
platform device when booting with EFI.

For these reasons, let's remove the register_gop_device() duplicated code
and instead move the platform specific logic that's there to sysfb driver.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625131359.1804394-1-javierm@redhat.com
2021-07-21 12:04:56 +02:00
Javier Martinez Canillas
d391c58271 drivers/firmware: move x86 Generic System Framebuffers support
The x86 architecture has generic support to register a system framebuffer
platform device. It either registers a "simple-framebuffer" if the config
option CONFIG_X86_SYSFB is enabled, or a legacy VGA/VBE/EFI FB device.

But the code is generic enough to be reused by other architectures and can
be moved out of the arch/x86 directory.

This will allow to also support the simple{fb,drm} drivers on non-x86 EFI
platforms, such as aarch64 where these drivers are only supported with DT.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625130947.1803678-2-javierm@redhat.com
2021-07-21 12:04:56 +02:00
Christoph Hellwig
bf44e8cecc vgaarb: don't pass a cookie to vga_client_register
The VGA arbitration is entirely based on pci_dev structures, so just pass
that back to the set_vga_decode callback.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-8-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:29:10 +02:00
Christoph Hellwig
f6b1772b25 vgaarb: remove the unused irq_set_state argument to vga_client_register
All callers pass NULL as the irq_set_state argument, so remove it and
the ->irq_set_state member in struct vga_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-7-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:29:05 +02:00
Christoph Hellwig
b877947586 vgaarb: provide a vga_client_unregister wrapper
Add a trivial wrapper for the unregister case that sets all fields to
NULL.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-6-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:29:00 +02:00
Christoph Hellwig
6609176f56 vgaarb: cleanup vgaarb.h
Merge the different CONFIG_VGA_ARB ifdef blocks, remove superflous
externs, and regularize the stubs for !CONFIG_VGA_ARB.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-5-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:28:56 +02:00
Christoph Hellwig
45549c00d3 vgaarb: move the kerneldoc for vga_set_legacy_decoding to vgaarb.c
Kerneldoc comments should be at the implementation side, not in the
header just declaring the prototype.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-4-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:28:51 +02:00
Christoph Hellwig
b0b514abc4 vgaarb: remove vga_conflicts
vga_conflicts only has a single caller and none of the arch overrides
mentioned in the comment.  Just remove it and the thus dead check in the
caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-3-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:28:47 +02:00
Christoph Hellwig
77e21b50ac vgaarb: remove VGA_DEFAULT_DEVICE
The define is entirely unused.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716061634.2446357-2-hch@lst.de
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-21 10:28:42 +02:00
Juan A. Suarez Romero
26a4dc29b7 drm/v3d: Expose performance counters to userspace
The V3D engine has several hardware performance counters that can of
interest for userspace performance analysis tools.

This exposes new ioctls to create and destroy performance monitor
objects, as well as to query the counter values.

Each created performance monitor object has an ID that can be attached
to CL/CSD submissions, so the driver enables the requested counters when
the job is submitted, and updates the performance monitor values when
the job is done.

It is up to the user to ensure all the jobs have been finished before
getting the performance monitor values. It is also up to the user to
properly synchronize BCL jobs when submitting jobs with different
performance monitors attached.

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Emma Anholt <emma@anholt.net>
To: dri-devel@lists.freedesktop.org
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Acked-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210608111541.461991-1-jasuarez@igalia.com
2021-07-21 00:19:59 +01:00
Desmond Cheong Zhi Xi
56f0729a51 drm: protect drm_master pointers in drm_lease.c
drm_file->master pointers should be protected by
drm_device.master_mutex or drm_file.master_lookup_lock when being
dereferenced.

However, in drm_lease.c, there are multiple instances where
drm_file->master is accessed and dereferenced while neither lock is
held. This makes drm_lease.c vulnerable to use-after-free bugs.

We address this issue in 2 ways:

1. Add a new drm_file_get_master() function that calls drm_master_get
on drm_file->master while holding on to
drm_file.master_lookup_lock. Since drm_master_get increments the
reference count of master, this prevents master from being freed until
we unreference it with drm_master_put.

2. In each case where drm_file->master is directly accessed and
eventually dereferenced in drm_lease.c, we wrap the access in a call
to the new drm_file_get_master function, then unreference the master
pointer once we are done using it.

Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-6-desmondcheongzx@gmail.com
2021-07-20 20:22:19 +02:00
Desmond Cheong Zhi Xi
0b0860a3cf drm: serialize drm_file.master with a new spinlock
Currently, drm_file.master pointers should be protected by
drm_device.master_mutex when being dereferenced. This is because
drm_file.master is not invariant for the lifetime of drm_file. If
drm_file is not the creator of master, then drm_file.is_master is
false, and a call to drm_setmaster_ioctl will invoke
drm_new_set_master, which then allocates a new master for drm_file and
puts the old master.

Thus, without holding drm_device.master_mutex, the old value of
drm_file.master could be freed while it is being used by another
concurrent process.

However, it is not always possible to lock drm_device.master_mutex to
dereference drm_file.master. Through the fbdev emulation code, this
might occur in a deep nest of other locks. But drm_device.master_mutex
is also the outermost lock in the nesting hierarchy, so this leads to
potential deadlocks.

To address this, we introduce a new spin lock at the bottom of the
lock hierarchy that only serializes drm_file.master. With this change,
the value of drm_file.master changes only when both
drm_device.master_mutex and drm_file.master_lookup_lock are
held. Hence, any process holding either of those locks can ensure that
the value of drm_file.master will not change concurrently.

Since no lock depends on the new drm_file.master_lookup_lock, when
drm_file.master is dereferenced, but drm_device.master_mutex cannot be
held, we can safely protect the master pointer with
drm_file.master_lookup_lock.

Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-5-desmondcheongzx@gmail.com
2021-07-20 20:17:58 +02:00
Desmond Cheong Zhi Xi
1f7ef07cfa drm: add a locked version of drm_is_current_master
While checking the master status of the DRM file in
drm_is_current_master(), the device's master mutex should be
held. Without the mutex, the pointer fpriv->master may be freed
concurrently by another process calling drm_setmaster_ioctl(). This
could lead to use-after-free errors when the pointer is subsequently
dereferenced in drm_lease_owner().

The callers of drm_is_current_master() from drm_auth.c hold the
device's master mutex, but external callers do not. Hence, we implement
drm_is_current_master_locked() to be used within drm_auth.c, and
modify drm_is_current_master() to grab the device's master mutex
before checking the master status.

Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-4-desmondcheongzx@gmail.com
2021-07-20 20:15:20 +02:00
Desmond Cheong Zhi Xi
5eff9585de drm: avoid blocking in drm_clients_info's rcu section
Inside drm_clients_info, the rcu_read_lock is held to lock
pid_task()->comm. However, within this protected section, a call to
drm_is_current_master is made, which involves a mutex lock in a future
patch. However, this is illegal because the mutex lock might block
while in the RCU read-side critical section.

Since drm_is_current_master isn't protected by rcu_read_lock, we avoid
this by moving it out of the RCU critical section.

The following report came from intel-gfx ci's
igt@debugfs_test@read_all_entries testcase:

=============================
[ BUG: Invalid wait context ]
5.13.0-CI-Patchwork_20515+ #1 Tainted: G        W
-----------------------------
debugfs_test/1101 is trying to lock:
ffff888132d901a8 (&dev->master_mutex){+.+.}-{3:3}, at:
drm_is_current_master+0x1e/0x50
other info that might help us debug this:
context-{4:4}
3 locks held by debugfs_test/1101:
 #0: ffff88810fdffc90 (&p->lock){+.+.}-{3:3}, at:
 seq_read_iter+0x53/0x3b0
 #1: ffff888132d90240 (&dev->filelist_mutex){+.+.}-{3:3}, at:
 drm_clients_info+0x63/0x2a0
 #2: ffffffff82734220 (rcu_read_lock){....}-{1:2}, at:
 drm_clients_info+0x1b1/0x2a0
stack backtrace:
CPU: 8 PID: 1101 Comm: debugfs_test Tainted: G        W
5.13.0-CI-Patchwork_20515+ #1
Hardware name: Intel Corporation CometLake Client Platform/CometLake S
UDIMM (ERB/CRB), BIOS CMLSFWR1.R00.1263.D00.1906260926 06/26/2019
Call Trace:
 dump_stack+0x7f/0xad
 __lock_acquire.cold.78+0x2af/0x2ca
 lock_acquire+0xd3/0x300
 ? drm_is_current_master+0x1e/0x50
 ? __mutex_lock+0x76/0x970
 ? lockdep_hardirqs_on+0xbf/0x130
 __mutex_lock+0xab/0x970
 ? drm_is_current_master+0x1e/0x50
 ? drm_is_current_master+0x1e/0x50
 ? drm_is_current_master+0x1e/0x50
 drm_is_current_master+0x1e/0x50
 drm_clients_info+0x107/0x2a0
 seq_read_iter+0x178/0x3b0
 seq_read+0x104/0x150
 full_proxy_read+0x4e/0x80
 vfs_read+0xa5/0x1b0
 ksys_read+0x5a/0xd0
 do_syscall_64+0x39/0xb0
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-3-desmondcheongzx@gmail.com
2021-07-20 20:14:42 +02:00
Desmond Cheong Zhi Xi
869e76f7a9 drm: avoid circular locks in drm_mode_getconnector
In preparation for a future patch to take a lock on
drm_device.master_mutex inside drm_is_current_master(), we first move
the call to drm_is_current_master() in drm_mode_getconnector out from the
section locked by &dev->mode_config.mutex. This avoids creating a
circular lock dependency.

Failing to avoid this lock dependency produces the following lockdep
splat:

======================================================
WARNING: possible circular locking dependency detected
5.13.0-rc7-CI-CI_DRM_10254+ #1 Not tainted
------------------------------------------------------
kms_frontbuffer/1087 is trying to acquire lock:
ffff88810dcd01a8 (&dev->master_mutex){+.+.}-{3:3}, at: drm_is_current_master+0x1b/0x40
but task is already holding lock:
ffff88810dcd0488 (&dev->mode_config.mutex){+.+.}-{3:3}, at: drm_mode_getconnector+0x1c6/0x4a0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&dev->mode_config.mutex){+.+.}-{3:3}:
       __mutex_lock+0xab/0x970
       drm_client_modeset_probe+0x22e/0xca0
       __drm_fb_helper_initial_config_and_unlock+0x42/0x540
       intel_fbdev_initial_config+0xf/0x20 [i915]
       async_run_entry_fn+0x28/0x130
       process_one_work+0x26d/0x5c0
       worker_thread+0x37/0x380
       kthread+0x144/0x170
       ret_from_fork+0x1f/0x30
-> #1 (&client->modeset_mutex){+.+.}-{3:3}:
       __mutex_lock+0xab/0x970
       drm_client_modeset_commit_locked+0x1c/0x180
       drm_client_modeset_commit+0x1c/0x40
       __drm_fb_helper_restore_fbdev_mode_unlocked+0x88/0xb0
       drm_fb_helper_set_par+0x34/0x40
       intel_fbdev_set_par+0x11/0x40 [i915]
       fbcon_init+0x270/0x4f0
       visual_init+0xc6/0x130
       do_bind_con_driver+0x1e5/0x2d0
       do_take_over_console+0x10e/0x180
       do_fbcon_takeover+0x53/0xb0
       register_framebuffer+0x22d/0x310
       __drm_fb_helper_initial_config_and_unlock+0x36c/0x540
       intel_fbdev_initial_config+0xf/0x20 [i915]
       async_run_entry_fn+0x28/0x130
       process_one_work+0x26d/0x5c0
       worker_thread+0x37/0x380
       kthread+0x144/0x170
       ret_from_fork+0x1f/0x30
-> #0 (&dev->master_mutex){+.+.}-{3:3}:
       __lock_acquire+0x151e/0x2590
       lock_acquire+0xd1/0x3d0
       __mutex_lock+0xab/0x970
       drm_is_current_master+0x1b/0x40
       drm_mode_getconnector+0x37e/0x4a0
       drm_ioctl_kernel+0xa8/0xf0
       drm_ioctl+0x1e8/0x390
       __x64_sys_ioctl+0x6a/0xa0
       do_syscall_64+0x39/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of: &dev->master_mutex --> &client->modeset_mutex --> &dev->mode_config.mutex
 Possible unsafe locking scenario:
       CPU0                    CPU1
       ----                    ----
  lock(&dev->mode_config.mutex);
                               lock(&client->modeset_mutex);
                               lock(&dev->mode_config.mutex);
  lock(&dev->master_mutex);
*** DEADLOCK ***
1 lock held by kms_frontbuffer/1087:
 #0: ffff88810dcd0488 (&dev->mode_config.mutex){+.+.}-{3:3}, at: drm_mode_getconnector+0x1c6/0x4a0
stack backtrace:
CPU: 7 PID: 1087 Comm: kms_frontbuffer Not tainted 5.13.0-rc7-CI-CI_DRM_10254+ #1
Hardware name: Intel Corporation Ice Lake Client Platform/IceLake U DDR4 SODIMM PD RVP TLC, BIOS ICLSFWR1.R00.3234.A01.1906141750 06/14/2019
Call Trace:
 dump_stack+0x7f/0xad
 check_noncircular+0x12e/0x150
 __lock_acquire+0x151e/0x2590
 lock_acquire+0xd1/0x3d0
 __mutex_lock+0xab/0x970
 drm_is_current_master+0x1b/0x40
 drm_mode_getconnector+0x37e/0x4a0
 drm_ioctl_kernel+0xa8/0xf0
 drm_ioctl+0x1e8/0x390
 __x64_sys_ioctl+0x6a/0xa0
 do_syscall_64+0x39/0xb0
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-2-desmondcheongzx@gmail.com
2021-07-20 20:13:56 +02:00
Jim Cromie
51fdf0914f drm/print: fixup spelling in a comment
s/prink/printk/ - no functional changes

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714175138.319514-2-jim.cromie@gmail.com
2021-07-20 15:08:18 +02:00
Guangming Cao
63c57e8dc7 dma_buf: remove dmabuf sysfs teardown before release
Dmabuf sysfs stat is used for dmabuf info track.
But these file maybe still in use after buffer released,
should clear it before buffer release.

Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210720103158.83439-1-guangming.cao@mediatek.com
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-20 12:59:55 +02:00
Yang Yingliang
b46998d81a drm/bochs: Fix missing pci_disable_device() on error in bochs_pci_probe()
Replace pci_enable_device() with pcim_enable_device(),
pci_disable_device() will be called in release automatically.

v3:
  reformat commit message
  update for move to tiny/
v2:
  use pcim_enable_device()

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210715132845.2415619-1-yangyingliang@huawei.com
2021-07-20 11:19:57 +02:00
KuoHsiang Chou
f34bf652d6 drm/ast: Disable fast reset after DRAM initial
[Bug][AST2500]

V1:
When AST2500 acts as stand-alone VGA so that DRAM and DVO initialization
have to be achieved by VGA driver with P2A (PCI to AHB) enabling.
However, HW suggests disable Fast reset mode after DRAM initializaton,
because fast reset mode is mainly designed for ARM ICE debugger.
Once Fast reset is checked as enabling, WDT (Watch Dog Timer) should be
first enabled to avoid system deadlock before disable fast reset mode.

V2:
Use to_pci_dev() to get revision of PCI configuration.

V3:
If SCU00 is not unlocked, just enter its password again.
It is unnecessary to clear AHB lock condition and restore WDT default
setting again, before Fast-reset clearing.

V4:
repatch after "error : could not build fake ancestor" resolved.

V5:
Since CVE_2019_6260 item3, Most of AST2500 have disabled P2A(PCIe to AMBA).
However, for backward compatibility, some patches about P2A, such as items
of v5.2 and v5.3, are considered to be upstreamed with comments.
1. Add define macro to improve source readability.
ast_drv.h, ast_main.c, ast_post.c
2. Add comment about "Fast restet" is enabled for ARM-ICE debugger
ast_post.c
3. Add comment about Reset USB port to patch USB unknown device issue
ast_post.c

Signed-off-by: KuoHsiang Chou <kuohsiang_chou@aspeedtech.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210709080900.4056-1-kuohsiang_chou@aspeedtech.com
2021-07-20 11:19:57 +02:00
Ainux.Wang
572994bf18 drm/ast: Zero is missing in detect function
The function ast_get_modes() will also return 0, when it try to get the
edid, but it also do not get the edid.

Signed-off-by: Ainux.Wang <ainux.wang@gmail.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716015615.9150-1-ainux.wang@gmail.com
2021-07-20 11:19:57 +02:00
Hridya Valsaraju
c715def515 dma-buf: Delete the DMA-BUF attachment sysfs statistics
The DMA-BUF attachment statistics form a subset of the DMA-BUF
sysfs statistics that recently merged to the drm-misc tree. They are not
UABI yet since they have not merged to the upstream Linux kernel.

Since there has been a reported a performance regression due to the
overhead of sysfs directory creation/teardown during
dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF
attachment statistics from sysfs.

Fixes: bdb8d06dfe ("dmabuf: Add the capability to expose DMA-BUF stats in sysfs")
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210713040742.2680135-1-hridya@google.com
Signed-off-by: Christian König <christian.koenig@amd.com>
2021-07-20 11:06:59 +02:00
Thomas Zimmermann
613ba71619
drm/ingenic: Convert to Linux IRQ interfaces
Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
don't benefit from using it.

This patch also fixes a bug where the driver didn't release the
IRQ.

v2:
	* automatically release IRQ via devm_request_irq() (Paul)
	* mention the bugfix (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210715100258.6638-1-tzimmermann@suse.de
2021-07-19 21:50:50 +01:00
Xiyu Yang
0189cb57b9 fbmem: Convert from atomic_t to refcount_t on fb_info->count
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1626674392-55857-1-git-send-email-xiyuyang19@fudan.edu.cn
2021-07-19 22:16:35 +02:00
Zheyu Ma
98a6543917 video: fbdev: kyro: fix a DoS bug by restricting user input
The user can pass in any value to the driver through the 'ioctl'
interface. The driver dost not check, which may cause DoS bugs.

The following log reveals it:

divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476
Call Trace:
 kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline]
 kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603
 do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171
 fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1626235762-2590-1-git-send-email-zheyuma97@gmail.com
2021-07-19 20:46:32 +02:00
Antonio Borneo
5cc4e71f01 drm/stm: dsi: compute the transition time from LP to HS and back
The driver uses a conservative set of hardcoded values for the
maximum time delay of the transitions between LP and HS, either
for data and clock lanes.

By using the info in STM32MP157 datasheet, valid also for other ST
devices, compute the actual delay from the lane's bps.

Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: Philippe Cornu <philippe.cornu@foss.st.com>
Acked-by: Philippe Cornu <philippe.cornu@foss.st.com>
Signed-off-by: Philippe Cornu <philippe.cornu@foss.st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210713144941.3599-1-antonio.borneo@foss.st.com
2021-07-19 15:35:55 +02:00
Jagan Teki
648ce7fd18 drm/stm: ltdc: Silence -EPROBE_DEFER till bridge attached
As dw-mipi-dsi supported all possible ways to find the DSI
devices. It can take multiple iterations for ltdc to find
all components attached to the DSI bridge.

The current ltdc driver failed to find the endpoint as
it returned -EINVAL for the first iteration itself. This leads
to following error:

[    3.099289] [drm:ltdc_load] *ERROR* init encoder endpoint 0

So, check the return value and cleanup the encoder only if it's
not -EPROBE_DEFER. This make all components in the attached DSI
bridge found properly.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Yannick Fertre <yannick.fertre@foss.st.com>
Acked-by: Philippe Cornu <philippe.cornu@foss.st.com>
Signed-off-by: Philippe Cornu <philippe.cornu@foss.st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210704135914.268308-1-jagan@amarulasolutions.com
2021-07-19 15:31:56 +02:00
Linus Walleij
57f6190a60 drm/panel: ws2401: Add driver for WideChips WS2401
This adds a driver for panels based on the WideChips WS2401 display
controller. This display controller is used in the Samsung LMS380KF01
display found in the Samsung GT-I8160 (Codina) mobile phone and
possibly others.

As is common with Samsung displays manufacturer commands are necessary
to configure the display to a working state.

The display optionally supports internal backlight control, but can
also use an external backlight.

This driver re-uses the DBI infrastructure to communicate with the
display.

Cc: phone-devel@vger.kernel.org
Cc: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714225002.1065107-2-linus.walleij@linaro.org
2021-07-17 13:10:29 +02:00
Linus Walleij
f82ff130a5 drm/panel: Add DT bindings for Samsung LMS380KF01
This adds device tree bindings for the Samsung Mobile Displays
LMS380KF01 RGB DPI display panel.

Cc: devicetree@vger.kernel.org
Cc: phone-devel@vger.kernel.org
Cc: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714225002.1065107-1-linus.walleij@linaro.org
2021-07-17 13:10:27 +02:00
Douglas Anderson
17a1837d07 drm/dp: For drm_panel_dp_aux_backlight(), init backlight as disabled
Even after the DP AUX backlight on my board worked OK after applying
the patch ("drm/panel-simple: Power the panel when probing DP AUX
backlight") [1], I still noticed some strange timeouts being reported
by ti_sn_aux_transfer(). Digging, I realized the problem was this:
* Even though `enabled` in `struct dp_aux_backlight` was false, the
  base backlight structure (`base` in that structure) thought that the
  backlight was powered on.
* If userspace wrote to sysfs in this state then we'd try to enable
  the backlight.
* Unfortunatley, enabling the backlight didn't work because the panel
  itself wasn't powered.

We can only use the backlight if the panel is on and the panel is not
officially on when we probe (it's temporarily just on enough for us to
talk to it).

The important thing we want here is to get `BL_CORE_FBBLANK` set since
userspace can't mess with that. This will keep us disabled until
drm_panel enables us, which means that the panel is enabled
first. Ideally we'd just set this in our `props` before calling
devm_backlight_device_register() but the comments in the header file
are pretty explicit that we're not supposed to much with the `state`
ourselves. Because of this, there may be a small window where the
backlight device is registered and someone could try to tweak with the
backlight. This isn't likely to happen and even if it did, I don't
believe this causes any huge problem.

[1] https://lore.kernel.org/lkml/20210714093334.1.Idb41f87e5abae4aee0705db7458b0097fc50e7ab@changeid/

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714101744.1.Ifc22696b27930749915e383f0108b7bcdc015a6e@changeid
2021-07-15 08:03:29 -07:00