linux-stable.git/drivers/video/backlight, branch v4.14.331

backlight/lv5207lp: Compare against struct fb_info.device

2023-09-23T08:47:00+00:00

commit 1ca8819320fd84e7d95b04e7668efc5f9fe9fa5c upstream.

Struct lv5207lp_platform_data refers to a platform device within
the Linux device hierarchy. The test in lv5207lp_backlight_check_fb()
compares it against the fbdev device in struct fb_info.dev, which
is different. Fix the test by comparing to struct fb_info.device.

Fixes a bug in the backlight driver and prepares fbdev for making
struct fb_info.dev optional.

v2:
	* move renames into separate patch (Javier, Sam, Michael)

Fixes: 82e5c40d88f9 ("backlight: Add Sanyo LV5207LP backlight driver")
Signed-off-by: Thomas Zimmermann 
Cc: Laurent Pinchart 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: John Paul Adrian Glaubitz 
Cc: Lee Jones 
Cc: Daniel Thompson 
Cc: Jingoo Han 
Cc: linux-sh@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc:  # v3.12+
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Sam Ravnborg 
Reviewed-by: Daniel Thompson 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-6-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman

backlight/bd6107: Compare against struct fb_info.device

2023-09-23T08:47:00+00:00

commit 992bdddaabfba19bdc77c1c7a4977b2aa41ec891 upstream.

Struct bd6107_platform_data refers to a platform device within
the Linux device hierarchy. The test in bd6107_backlight_check_fb()
compares it against the fbdev device in struct fb_info.dev, which
is different. Fix the test by comparing to struct fb_info.device.

Fixes a bug in the backlight driver and prepares fbdev for making
struct fb_info.dev optional.

v2:
	* move renames into separate patch (Javier, Sam, Michael)

Fixes: 67b43e590415 ("backlight: Add ROHM BD6107 backlight driver")
Signed-off-by: Thomas Zimmermann 
Cc: Laurent Pinchart 
Cc: Lee Jones 
Cc: Daniel Thompson 
Cc: Jingoo Han 
Cc: dri-devel@lists.freedesktop.org
Cc:  # v3.12+
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Sam Ravnborg 
Reviewed-by: Daniel Thompson 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-2-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman

backlight/gpio_backlight: Compare against struct fb_info.device

2023-09-23T08:47:00+00:00

commit 7b91d017f77c1bda56f27c2f4bbb70de7c6eca08 upstream.

Struct gpio_backlight_platform_data refers to a platform device within
the Linux device hierarchy. The test in gpio_backlight_check_fb()
compares it against the fbdev device in struct fb_info.dev, which
is different. Fix the test by comparing to struct fb_info.device.

Fixes a bug in the backlight driver and prepares fbdev for making
struct fb_info.dev optional.

v2:
	* move renames into separate patch (Javier, Sam, Michael)

Signed-off-by: Thomas Zimmermann 
Fixes: 8b770e3c9824 ("backlight: Add GPIO-based backlight driver")
Cc: Laurent Pinchart 
Cc: Rich Felker 
Cc: John Paul Adrian Glaubitz 
Cc: Lee Jones 
Cc: Daniel Thompson 
Cc: Jingoo Han 
Cc: linux-sh@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc:  # v3.12+
Reviewed-by: Sam Ravnborg 
Reviewed-by: Daniel Thompson 
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-4-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman

backlight: pwm_bl: Improve bootloader/kernel device handover

2021-09-22T09:45:23+00:00

commit 79fad92f2e596f5a8dd085788a24f540263ef887 upstream.

Currently there are (at least) two problems in the way pwm_bl starts
managing the enable_gpio pin. Both occur when the backlight is initially
off and the driver finds the pin not already in output mode and, as a
result, unconditionally switches it to output-mode and asserts the signal.

Problem 1: This could cause the backlight to flicker since, at this stage
in driver initialisation, we have no idea what the PWM and regulator are
doing (an unconfigured PWM could easily "rest" at 100% duty cycle).

Problem 2: This will cause us not to correctly honour the
post_pwm_on_delay (which also risks flickers).

Fix this by moving the code to configure the GPIO output mode until after
we have examines the handover state. That allows us to initialize
enable_gpio to off if the backlight is currently off and on if the
backlight is on.

Cc: stable@vger.kernel.org
Reported-by: Marek Vasut 
Signed-off-by: Daniel Thompson 
Acked-by: Marek Vasut 
Tested-by: Marek Vasut 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

backlight: lm3630a: Fix return code of .update_status() callback

2021-07-20T14:17:51+00:00

[ Upstream commit b9481a667a90ec739995e85f91f3672ca44d6ffa ]

According to  .update_status() is supposed to
return 0 on success and a negative error code otherwise. Adapt
lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status() to
actually do it.

While touching that also add the error code to the failure message.

Signed-off-by: Uwe Kleine-König 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: sky81452-backlight: Fix refcount imbalance on error

2020-10-29T08:07:04+00:00

[ Upstream commit b7a4f80bc316a56d6ec8750e93e66f42431ed960 ]

When of_property_read_u32_array() returns an error code, a
pairing refcount decrement is needed to keep np's refcount
balanced.

Fixes: f705806c9f355 ("backlight: Add support Skyworks SKY81452 backlight driver")
Signed-off-by: Dinghao Liu 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: lp855x: Ensure regulators are disabled on probe failure

2020-06-25T13:41:47+00:00

[ Upstream commit d8207c155a7c6015eb7f43739baa7dfb1fa638af ]

If probing the LP885x backlight fails after the regulators have been
enabled, then the following warning is seen when releasing the
regulators ...

 WARNING: CPU: 1 PID: 289 at drivers/regulator/core.c:2051 _regulator_put.part.28+0x158/0x160
 Modules linked in: tegra_xudc lp855x_bl(+) host1x pwm_tegra ip_tables x_tables ipv6 nf_defrag_ipv6
 CPU: 1 PID: 289 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200224 #1
 Hardware name: NVIDIA Jetson TX1 Developer Kit (DT)

 ...

 Call trace:
  _regulator_put.part.28+0x158/0x160
  regulator_put+0x34/0x50
  devm_regulator_release+0x10/0x18
  release_nodes+0x12c/0x230
  devres_release_all+0x34/0x50
  really_probe+0x1c0/0x370
  driver_probe_device+0x58/0x100
  device_driver_attach+0x6c/0x78
  __driver_attach+0xb0/0xf0
  bus_for_each_dev+0x68/0xc8
  driver_attach+0x20/0x28
  bus_add_driver+0x160/0x1f0
  driver_register+0x60/0x110
  i2c_register_driver+0x40/0x80
  lp855x_driver_init+0x20/0x1000 [lp855x_bl]
  do_one_initcall+0x58/0x1a0
  do_init_module+0x54/0x1d0
  load_module+0x1d80/0x21c8
  __do_sys_finit_module+0xe8/0x100
  __arm64_sys_finit_module+0x18/0x20
  el0_svc_common.constprop.3+0xb0/0x168
  do_el0_svc+0x20/0x98
  el0_sync_handler+0xf4/0x1b0
  el0_sync+0x140/0x180

Fix this by ensuring that the regulators are disabled, if enabled, on
probe failure.

Finally, ensure that the vddio regulator is disabled in the driver
remove handler.

Signed-off-by: Jon Hunter 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: lm3630a: Return 0 on success in update_status functions

2020-01-27T13:46:34+00:00

[ Upstream commit d3f48ec0954c6aac736ab21c34a35d7554409112 ]

lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status()
both return the brightness value if the brightness was successfully
updated. Writing to these attributes via sysfs would cause a 'Bad
address' error to be returned. These functions should return 0 on
success, so let's change it to correct that error.

Fixes: 28e64a68a2ef ("backlight: lm3630: apply chip revision")
Signed-off-by: Brian Masney 
Acked-by: Pavel Machek 
Acked-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: lm3639: Unconditionally call led_classdev_unregister

2019-11-24T07:23:24+00:00

[ Upstream commit 7cea645ae9c5a54aa7904fddb2cdf250acd63a6c ]

Clang warns that the address of a pointer will always evaluated as true
in a boolean context.

drivers/video/backlight/lm3639_bl.c:403:14: warning: address of
'pchip->cdev_torch' will always evaluate to 'true'
[-Wpointer-bool-conversion]
        if (&pchip->cdev_torch)
        ~~   ~~~~~~~^~~~~~~~~~
drivers/video/backlight/lm3639_bl.c:405:14: warning: address of
'pchip->cdev_flash' will always evaluate to 'true'
[-Wpointer-bool-conversion]
        if (&pchip->cdev_flash)
        ~~   ~~~~~~~^~~~~~~~~~
2 warnings generated.

These statements have been present since 2012, introduced by
commit 0f59858d5119 ("backlight: add new lm3639 backlight
driver"). Given that they have been called unconditionally since
then presumably without any issues, removing the always true if
statements to fix the warnings without any real world changes.

Link: https://github.com/ClangBuiltLinux/linux/issues/119
Signed-off-by: Nathan Chancellor 
Reviewed-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

backlight: pwm_bl: Use gpiod_get_value_cansleep() to get initial state

2019-04-05T20:31:37+00:00

[ Upstream commit cec2b18832e26bc866bef2be22eff4e25bbc4034 ]

gpiod_get_value() gives out a warning if access to the underlying gpiochip
requires sleeping, which is common for I2C based chips:

    WARNING: CPU: 0 PID: 77 at drivers/gpio/gpiolib.c:2500 gpiod_get_value+0xd0/0x100
    Modules linked in:
    CPU: 0 PID: 77 Comm: kworker/0:2 Not tainted 4.14.0-rc3-00589-gf32897915d48-dirty #90
    Hardware name: Allwinner sun4i/sun5i Families
    Workqueue: events deferred_probe_work_func
    [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
    [] (show_stack) from [] (dump_stack+0x88/0x9c)
    [] (dump_stack) from [] (__warn+0xe8/0x100)
    [] (__warn) from [] (warn_slowpath_null+0x20/0x28)
    [] (warn_slowpath_null) from [] (gpiod_get_value+0xd0/0x100)
    [] (gpiod_get_value) from [] (pwm_backlight_probe+0x238/0x508)
    [] (pwm_backlight_probe) from [] (platform_drv_probe+0x50/0xac)
    [] (platform_drv_probe) from [] (driver_probe_device+0x238/0x2e8)
    [] (driver_probe_device) from [] (bus_for_each_drv+0x44/0x94)
    [] (bus_for_each_drv) from [] (__device_attach+0xb0/0x114)
    [] (__device_attach) from [] (bus_probe_device+0x84/0x8c)
    [] (bus_probe_device) from [] (deferred_probe_work_func+0x50/0x14c)
    [] (deferred_probe_work_func) from [] (process_one_work+0x1ec/0x414)
    [] (process_one_work) from [] (worker_thread+0x2b0/0x5a0)
    [] (worker_thread) from [] (kthread+0x14c/0x154)
    [] (kthread) from [] (ret_from_fork+0x14/0x24)

This was missed in commit 0c9501f823a4 ("backlight: pwm_bl: Handle gpio
that can sleep"). The code was then moved to a separate function in
commit 7613c922315e ("backlight: pwm_bl: Move the checks for initial power
state to a separate function").

The only usage of gpiod_get_value() is during the probe stage, which is
safe to sleep in. Switch to gpiod_get_value_cansleep().

Fixes: 0c9501f823a4 ("backlight: pwm_bl: Handle gpio that can sleep")
Signed-off-by: Chen-Yu Tsai 
Acked-by: Maxime Ripard 
Acked-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin