9c26be2c3e
commit 57435c42400ec147a527b2313188b649e81e449e upstream. n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.2.1.2 describes the encoding of the C/R (command/response) bit. Table 1 shows that the actual encoding of the C/R bit is inverted if the associated frame is sent by the responder. The referenced commit fixed here further broke the internal meaning of this bit in the outgoing path by always setting the C/R bit regardless of the frame type. This patch fixes both by setting the C/R bit always consistently for command (1) and response (0) frames and inverting it later for the responder where necessary. The meaning of this bit in the debug output is being preserved and shows the bit as if it was encoded by the initiator. This reflects only the frame type rather than the encoded combination of communication side and frame type. Fixes: cc0f42122a7e ("tty: n_gsm: Modify CR,PF bit when config requester") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220218073123.2121-2-daniel.starke@siemens.com 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
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.