f17bda7f65
The I2C-bus to the XPower AXP288 is shared between the Linux kernel and the SoCs P-Unit. The P-Unit has a semaphore which the kernel must "lock" before it may use the bus. This semaphore is automatically taken by the I2C-bus-driver. The retry on -EBUSY logic in fuel_gauge_reg_readb() likely was added to deal with the I2C-bus-drive returning -EBUSY when it failed to take the semaphore, but this really should never happen. The semaphore code even has a WARN_ON(ret) to log a kernel backtrace if this does somehow happen, when this happens something is seriously wrong and the system typically freezes soon afterwards. TL;DR: the regmap_read() should never fail with -EBUSY so the retries are unnecessary. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.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.