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e98d72d98a
The Orange Pi Plus board lacks voltage scaling capabilities in its current form. This results in random freezes during boot when cpufreq is enabled, probably due to wrong voltages. This patch (more or less copy/paste from 06139c) does the following things on this board: - enable r_i2c - add sy8106a to the r_i2c bus - have the sy8106a regulate VDD of cpu Since the Orange Pi Plus has the same PMU setup as the Orange Pi PC, I simply took min/max/fixed/ramp from the latter DTS. In that file the origin of the values are described by the following comment: "The datasheet uses 1.1V as the minimum value of VDD-CPUX, however both the Armbian DVFS table and the official one have operating points with voltage under 1.1V, and both DVFS table are known to work properly at the lowest operating point. Use 1.0V as the minimum voltage instead." I have tested this on patch two Orange Pi Plus boards, by running a kernel with this patch and do intermettent runs of cpuburn while monitoring voltage, frequency and temperature. The board runs stable across its operatiing points while showing a reasonable (< 40C) temperature. My Orange Pi PC, when put to the same test, yields similar stable results. Signed-off-by: Jorik Jonker <jorik@kippendief.biz> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.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.