mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-06 10:58:48 +09:00
0276f69f13
Currently we use predefined initial threshold values. This works, but does not really scale well with more and more SoCs gaining bwmon support, as the necessary kickoff values may differ between platforms due to memory type and/or controller setup. All of the data we need for that is already provided in the device tree, anyway. Change the thresholds to: * low = 0 (as we've been doing up until now) * med = high = BW_MIN Throughput going below the med threshold nudges bwmon into signaling that we should slow down (e.g. if we inherited too high bandwidth from the bootloader). Throughput going above the high threshold nudges bwmon into signaling that we should speed up so as not to choke the bus traffic due to insufficient transfer rates. F_MIN is a perfect initial value for both of these cases - if we go above it (and there's a 99.99% chance it'll happen at boot time), we should definitely make the memory go faster, whereas if we go below it, we should slow down, no matter what performance state we were at before (it's only possible for them to be >= FMIN). This only changes the values programmed at probe time, as high and med thresholds are updated at interrupt, also based on the OPP table from DT. Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> Reviewed-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20230610-topic-bwmon_opp-v2-1-0d25c1ce7dca@linaro.org Signed-off-by: Bjorn Andersson <andersson@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.