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Alex Elder says: ==================== net: qualcomm: rmnet: MAPv4 download checksum cleanup, part 1 I'm posting a large series an two smaller parts; this is part 1. The RMNet driver handles MAP (or QMAP) protocol traffic. There are several versions of this protocol. Version 1 supports multiplexing, as well as aggregation of packets in a single buffer. Version 4 adds the ability to perform checksum offload. And version 5 implements checksum offload in a different way from version 4. This series involves only MAPv4 protocol checksum offload, and only in the download (RX) direction. It affects handling of checksums computed by hardware for UDP datagrams and TCP segments, carried over both IPv4 and IPv6. MAP packets arriving on an RMNet port implementing MAPv4 checksum offload are passed to rmnet_map_checksum_downlink_packet() for handling. The packet is then passed to rmnet_map_ipv4_dl_csum_trailer() or rmnet_map_ipv6_dl_csum_trailer(), depending contents of the MAP payload. These two functions interpret checksum metadata to determine whether the checksum in the received packet matches that calculated by the hardware. It is these two functions that are the subject of this series (parts 1 and 2). The bulk of these functions are transformed--in a lot of small steps--from an extremely difficult-to-follow block of checksum processing code into a fairly simple, heavily commented equivalent. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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.