cd25507a31
The ice driver requires a cached copy of the PHC time in order to perform timestamp extension on Tx and Rx hardware timestamp values. This cached PHC time must always be updated at least once every 2 seconds. Otherwise, the math used to perform the extension would produce invalid results. The updates are supposed to occur periodically in the PTP kthread work item, which is scheduled to run every half second. Thus, we do not expect an update to be delayed for so long. However, there are error conditions which can cause the update to be delayed. Track this situation by using jiffies to determine approximately how long ago the last update occurred. Add a new statistic and a dev_warn when we have failed to update the cached PHC time. This makes the error case more obvious. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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.