f7adc73878
Handle custom baud rates requested in the UPF_MAGIC_MULTIPLIER range with BOTHER. Currently matching is exact, that is if a baud rate that is not either of clk/4 or clk/8 is requested, then we fall through to the default case, which will just divide the clock rate by 16 times the rate requested, round it to closest integer, and possibly yield even worse results then if clamping to the extra baud rates was chosen. So for example if we have the usual base rate of 115200 and request a rate of 230399, then the fall-through divisor calculation will yield 1, and consequently the baud rate of 115200 will be programmed even though obviously the magic rate of 230400 would be more appropriate. Make the selection of the magic rates range-qualified then and use clk/4 for rates from clk/6 up (assuming `serial8250_get_baud_rate' has already rejected any rates too far beyond clk/4), and otherwise use clk/8 for rates from clk/12 up, and finally fall through to the standard divisor calculation. Explicitly void using the undocumented rate of 153600bps and stick to documented divisor values only. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2105200232090.29169@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.