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0580baa46e
A subset of all CH341 devices don't support a real break condition. This fact is already used in the "ch341_detect_quirks" function. With this change a quirk is implemented to simulate a break condition by temporarily lowering the baud rate and sending a NUL byte. The primary drawbacks of this approach are that the duration of the break can't be controlled by userland and that data incoming during a simulated break is corrupted. The "TTY_DRIVER_HARDWARE_BREAK" serial driver flag was investigated as an alternative. It's a driver-wide flag and would've required significant changes to the serial and USB-serial driver frameworks to expose it for individual USB-serial adapters. Tested by sending a break condition and watching the TX pin using an oscilloscope. Signed-off-by: Michael Hanselmann <public@hansmi.ch> Link: https://lore.kernel.org/r/f34a9b6e-ec2a-0873-e97b-2d5b2170e2ff@msgid.hansmi.ch [ johan: condense info message ] Signed-off-by: Johan Hovold <johan@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.