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Charles Keepax authored
The GPIO framework supports specifying if a GPIO is active low or
high and will invert accordingly. Whilst specifying this is part of
the normal GPIO definition flow on device tree systems, it is a DSD
extension under ACPI, that Windows doesn't really use. This means most
ACPI systems do not set the polarity of the pin.

The current cs42l43 driver assumes it is setting the level of the line
directly, which is actually the case on all current systems and likely
most future ones. However if the part was used in a device tree system
or an ACPI system that actually used the DSD extensions this would get
inverted, causing the driver to fail probe. As the driver always knows
the polarity of its own reset line, use the raw set API making the
intention to set the level directly clear and to avoid any such future
issues.

Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20241205115822.2371719-2-ckeepax@opensource.cirrus.com


Signed-off-by: default avatarLee Jones <lee@kernel.org>
a57f93b7
History
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 reStructuredText 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.