b1a582e64b
If the PTP hardware clock is adjusted, the ice driver must update the cached PHC timestamp. This is required in order to perform timestamp extension on the shorter timestamps captured by the PHY. Currently, we simply call ice_ptp_update_cached_phctime in the settime and adjtime callbacks. This has a few issues: 1) if ICE_CFG_BUSY is set because another thread is updating the Rx rings, we will exit with an error. This is not checked, and the functions do not re-schedule the update. This could leave the cached timestamp incorrect until the next scheduled work item execution. 2) even if we did handle an update, any currently outstanding Tx timestamp would be extended using the wrong cached PHC time. This would produce incorrect results. To fix these issues, introduce a new ice_ptp_reset_cached_phctime function. This function calls the ice_ptp_update_cached_phctime, and discards outstanding Tx timestamps. If the ice_ptp_update_cached_phctime function fails because ICE_CFG_BUSY is set, we log a warning and schedule the thread to execute soon. The update function is modified so that it always updates the cached copy in the PF regardless. This ensures we have the most up to date values possible and minimizes the risk of a packet timestamp being extended with the wrong value. It would be nice if we could skip reporting Rx timestamps until the cached values are up to date. However, we can't access the Rx rings while ICE_CFG_BUSY is set because they are actively being updated by another thread. 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.