Ingo van Lil
9d39d86cd4
Pull-ups for SAM9 UART/USART TX lines were disabled in a previous
commit. However, several chips in the SAM9 family require pull-ups to
prevent the TX lines from falling (and causing an endless break
condition) when the transceiver is disabled.
From the SAM9G20 datasheet, 32.5.1: "To prevent the TXD line from
falling when the USART is disabled, the use of an internal pull up
is mandatory.". This commit reenables the pull-ups for all chips having
that sentence in their datasheets.
Fixes: 5e04822f7d ("ARM: dts: at91: fixes uart pinctrl, set pullup on rx, clear pullup on tx")
Signed-off-by: Ingo van Lil <inguin@gmx.de>
Cc: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20191203142147.875227-1-inguin@gmx.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
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.