42a55435b0
The max2175 uses a flat register cache but supplies only a single default value and has many volatile registers. This is a poor fit for a flat cache since the cache will assume a default of zero for any register not yet written which can lead to bugs for example when regmap_update_bits() suppresses a noop write. A rbtree cache is a much better fit, this will only cache default values and values that have been written to the device with any reads of uncached values going to the hardware. Convert the driver to use a rbtree cache. Since the device is controlled via I2C the cost of manging the rbtree should be immaterial compared to the cost of accessing the device. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
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.