e89ecd8368
For i.MX8MP, we cannot ensure that cycle counter overflow occurs at least 4 times as often as other events. Due to byte counters will count for any event configured, it will overflow more often. And if byte counters overflow that related counters would stop since they share the COUNTER_CNTL. We can speed up cycle counter overflow frequency by setting counter parameter (CP) field of cycle counter. In this way, we can avoid stop counting byte counters when interrupt didn't come and the byte counters can be fetched or updated from each cycle counter overflow interrupt. Because we initialize CP filed to shorten counter0 overflow time, the cycle counter will start couting from a fixed/base value each time. We need to remove the base from the result too. Therefore, we could get precise result from cycle counter. Signed-off-by: Xu Yang <xu.yang_2@nxp.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20230811015438.1999307-1-xu.yang_2@nxp.com Signed-off-by: Will Deacon <will@kernel.org>
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.