mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-06 01:49:46 +00:00
58578eabf8
[ Upstream commitb234fe9558] During cpu frequency switching the main "CLK_ARM" is reparented to an intermediate "step" clock. On imx8mm and imx8mn the 24M oscillator is used for this purpose but it is extremely slow, increasing wakeup latencies to the point that i2c transactions can timeout and system becomes unresponsive. Fix by switching the "step" clk to SYS_PLL1_800M, matching the behavior of imx8m cpufreq drivers in imx vendor tree. This bug was not immediately apparent because upstream arm64 defconfig uses the "performance" governor by default so no cpufreq transitions happen. Fixes:ba5625c3e2("clk: imx: Add clock driver support for imx8mm") Fixes:96d6392b54("clk: imx: Add support for i.MX8MN clock driver") Cc: stable@vger.kernel.org Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Link: https://lkml.kernel.org/r/f5d2b9c53f1ed5ccb1dd3c6624f56759d92e1689.1571771777.git.leonard.crestez@nxp.com Acked-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Sasha Levin <sashal@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.