fa7501e57e
The only user of tty_ops::chars_in_buffer is tty_chars_in_buffer. And it considers tty_ops::chars_in_buffer optional. In case it's NULL, zero is returned. So remove all those chars_in_buffer from tty_ops which return zero. (Zero means such driver doesn't buffer.) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Richard Henderson <rth@twiddle.net> Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Chris Zankel <chris@zankel.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Link: https://lore.kernel.org/r/20210505091928.22010-26-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.