linux-stable.git/drivers/video/backlight, branch linux-4.9.y

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

2021-07-20T14:21:12+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

2020-10-29T08:05:34+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

2020-06-30T19:38:20+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

2020-01-29T09:24:24+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

2019-11-25T08:53:44+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

pwm-backlight: Enable/disable the PWM before/after LCD enable toggle.

2019-03-27T05:13:04+00:00

commit 5fb5caee92ba35a4a3baa61d45a78eb057e2c031 upstream.

Before this patch the enable signal was set before the PWM signal and
vice-versa on power off. This sequence is wrong, at least, it is on
the different panels datasheets that I checked, so I inverted the sequence
to follow the specs.

For reference the following panels have the mentioned sequence:
  - N133HSE-EA1 (Innolux)
  - N116BGE (Innolux)
  - N156BGE-L21 (Innolux)
  - B101EAN0 (Auo)
  - B101AW03 (Auo)
  - LTN101NT05 (Samsung)
  - CLAA101WA01A (Chunghwa)

Signed-off-by: Enric Balletbo i Serra 
Acked-by: Daniel Thompson 
Acked-by: Jingoo Han 
Acked-by: Thierry Reding 
Signed-off-by: Lee Jones 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

backlight: tps65217_bl: Fix Device Tree node lookup

2018-07-03T09:23:14+00:00

commit 2b12dfa124dbadf391cb9a616aaa6b056823bf75 upstream.

Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

This would only cause trouble if the child node is missing while there
is an unrelated node named "backlight" elsewhere in the tree.

Cc: stable      # 3.7
Fixes: eebfdc17cc6c ("backlight: Add TPS65217 WLED driver")
Signed-off-by: Johan Hovold 
Acked-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

backlight: max8925_bl: Fix Device Tree node lookup

2018-07-03T09:23:14+00:00

commit d1cc0ec3da23e44c23712579515494b374f111c9 upstream.

Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

To make things worse, the parent mfd node was also prematurely freed,
while the child backlight node was leaked.

Cc: stable      # 3.9
Fixes: 47ec340cb8e2 ("mfd: max8925: Support dt for backlight")
Signed-off-by: Johan Hovold 
Acked-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

backlight: as3711_bl: Fix Device Tree node lookup

2018-07-03T09:23:14+00:00

commit 4a9c8bb2aca5b5a2a15744333729745dd9903562 upstream.

Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

To make things worse, the parent mfd node was also prematurely freed.

Cc: stable      # 3.10
Fixes: 59eb2b5e57ea ("drivers/video/backlight/as3711_bl.c: add OF support")
Signed-off-by: Johan Hovold 
Acked-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Greg Kroah-Hartman

backlight: Report error on failure

2018-04-13T17:48:13+00:00

[ Upstream commit 7e715c2d9c27c23f3187454157c58cf292ed103e ]

It is possible to update the backlight power and the brightness using
the sysfs and on writing it either returns the count or if the callback
function does not exist then returns the error code 'ENXIO'.

We have a situation where the userspace client is writing to the sysfs
to update the power and since the callback function exists the client
receives the return value as count and considers the operation to be
successful. That is correct as the write to the sysfs was successful.
But there is no way to know if the actual operation was done or not.

backlight_update_status() returns the error code if it fails. Pass that
to the userspace client who is trying to update the power so that the
client knows that the operation failed.

Signed-off-by: Sudip Mukherjee 
Acked-by: Daniel Thompson 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman