bbd2763ac8
[ Upstream commit 76fe464c8e64e71b2e4af11edeef0e5d85eeb6aa ]
Disabling a PWM (i.e. calling pwm_apply_state with .enabled = false)
gives no guarantees what the PWM output does. It might freeze where it
currently is, or go in a High-Z state or drive the active or inactive
state, it might even continue to toggle.
To ensure that the LED gets really disabled, don't disable the PWM even
when .duty_cycle is zero.
This fixes disabling a leds-pwm LED on i.MX28. The PWM on this SoC is
one of those that freezes its output on disable, so if you disable an
LED that is full on, it stays on. If you disable a LED with half
brightness it goes off in 50% of the cases and full on in the other 50%.
Fixes: 41c42ff5dbe2 ("leds: simple driver for pwm driven LEDs")
Reported-by: Rogan Dawes <rogan@dawes.za.net>
Reported-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Fabio Estevam <festevam@denx.de>
Link: https://lore.kernel.org/r/20230922192834.1695727-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.