[PATCH] docs: admin-guide: fix serial default / maximum
From: Samuel Dionne-Riel <hidden>
Date: 2021-08-19 23:35:22
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
The defaults and maximum described here are not right. E.g. the default for amba-pl* is 38400, and meson_uart is 115200. Finding out likely defaults can be done with the following grep $ grep -R 'int\s*baud\s*=\s*[0-9]\+' drivers/tty/serial/ While not all results will be in the .setup function for the console, many are. As for maximums, I couldn't trivially find out if 8250 does have a maximum defined in the kernel driver, but some platforms do go higher, e.g. the common baud rate for Rockchip hardware is 1500000. Signed-off-by: Samuel Dionne-Riel <redacted> --- Documentation/admin-guide/kernel-parameters.txt | 2 +- Documentation/admin-guide/serial-console.rst | 5 +++-- 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index cb89dbdedc463..6e0f8a8229bca 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt@@ -649,7 +649,7 @@ the form "bbbbpnf", where "bbbb" is the baud rate, "p" is parity ("n", "o", or "e"), "n" is number of bits, and "f" is flow control ("r" for RTS or - omit it). Default is "9600n8". + omit it). Default depends on the driver. See Documentation/admin-guide/serial-console.rst for more information. See
diff --git a/Documentation/admin-guide/serial-console.rst b/Documentation/admin-guide/serial-console.rst
index 58b32832e50aa..41977dd13ab7e 100644
--- a/Documentation/admin-guide/serial-console.rst
+++ b/Documentation/admin-guide/serial-console.rst@@ -29,8 +29,9 @@ The format of this option is:: defines the baudrate/parity/bits/flow control of the port, in the format BBBBPNF, where BBBB is the speed, P is parity (n/o/e), N is number of bits, - and F is flow control ('r' for RTS). Default is - 9600n8. The maximum baudrate is 115200. + and F is flow control ('r' for RTS). Default depends + on the driver. The maximum baudrate depends on the + device. You can specify multiple console= options on the kernel command line. Output will appear on all of them. The last device will be used when
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2.32.0