90188fff65
Rx Timestamping is done through 4 additional bytes in tail tag. Whenever the ptp packet is received, the 4 byte hardware time stamped value is added before 1 byte tail tag. Also, bit 7 in tail tag indicates it as PTP frame. This 4 byte value is extracted from the tail tag and reconstructed to absolute time and assigned to skb hwtstamp. If the packet received in PDelay_Resp, then partial ingress timestamp is subtracted from the correction field. Since user space tools expects to be done in hardware. Signed-off-by: Christian Eggers <ceggers@arri.de> Co-developed-by: Arun Ramadoss <arun.ramadoss@microchip.com> Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> 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.