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40a6b9a009
It turns out that commit 01ccf903ed ("pwm: Let pwm_get_state() return
the last implemented state") causes backlight failures on a number of
boards. The reason is that some of the drivers do not write the full
state through to the hardware registers, which means that ->get_state()
subsequently does not return the correct state. Consumers which rely on
pwm_get_state() returning the current state will therefore get confused
and subsequently try to program a bad state.
Before this change can be made, existing drivers need to be more
carefully audited and fixed to behave as the framework expects. Until
then, keep the original behaviour of returning the software state that
was applied rather than reading the state back from hardware.
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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.