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c0c0b03ea1
commit 81100b9a7b0515132996d62a7a676a77676cb6e3 upstream.
On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there
are multiple ways to configure the requested serial speed. If firmware
uses a different method than Linux, and if any debug info is printed
after the Bit Rate Register (SCBRR) is restored, but before termios is
reconfigured (which configures the alternative method), the system may
lock-up during resume.
Fix this by saving and restoring the contents of the BRG Frequency
Division (SCDL) and Clock Select (SCCKS) registers as well.
Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which
configures the sampling point, and the SCIFA/SCIFB's Serial Port Control
and Data Registers (SCPCR/SCPDR), which configure the optional control
flow signals.
After this, all registers that are not saved/restored are either:
- read-only,
- write-only,
- status registers containing flags with clear-after-set semantics,
- FIFO Data Count Trigger registers, which do not matter much for
the serial console.
Fixes: 22a6984c5b5df8ea ("serial: sh-sci: Update the suspend/resume support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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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.