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e4c8ae3e3d
linux/drivers/video
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Heiko Stuebner e4c8ae3e3d backlight: pwm_bl: Re-add driver internal enabled tracking 
Commit e6bcca0890 ("backlight: pwm_bl: Switch to using "atomic" PWM API")
removed the driver internal enabled tracking in favor of simply checking
the pwm state.

This can lead to issues as all of gpio-, regulator- and pwm-state are used
to determine the initial state and the bootloader or kernel can leave them
in an inconsistent state at boot.

In my case on rk3399-kevin, the pwm backlight is build as module and the
kernel disables the supply regulator as unused while keeping the pwm running
thus pwm_bl calling pwm_backlight_power_off() during probe and creating an
unmatched regulator-disable call, as it never got enabled from the pwm-bl
before.

To prevent these consistency issues, reintroduce the driver-internal
tracking of the enabled state.

Fixes: e6bcca0890 ("backlight: pwm_bl: Switch to using "atomic" PWM API")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>

Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-11-27 12:10:51 +00:00
..
backlight backlight: pwm_bl: Re-add driver internal enabled tracking 2018-11-27 12:10:51 +00:00
console dummycon: Stop exporting dummycon_[un]register_output_notifier 2018-08-10 17:23:02 +02:00
fbdev fbdev changes for v4.20: 2018-10-31 11:41:37 -07:00
logo video/logo: remove obsolete logo files 2018-03-26 15:56:42 +02:00
display_timing.c
hdmi.c media: hdmi.h: rename ADOBE_RGB to OPRGB and ADOBE_YCC to OPYCC 2018-09-24 09:28:41 -04:00
Kconfig fbdev changes for v4.17: 2018-04-10 10:20:00 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
of_display_timing.c fbdev: Convert to using %pOFn instead of device_node.name 2018-10-08 12:57:36 +02:00
of_videomode.c video: fbdev: Convert to using %pOF instead of full_name 2017-08-07 17:22:13 +02:00
vgastate.c Video: vgastate: fixed a spacing coding style 2018-10-08 12:57:35 +02:00
videomode.c