d938a8cca8
There is a problem in HW in E822-based devices leading to race condition. It might happen that, in order: - PF0 (which owns the PHC) requests few timestamps, - PF1 requests a timestamp, - interrupt is being triggered and both PF0 and PF1 threads are woken up, - PF0 got one timestamp, still waiting for others so not going to sleep, - PF1 gets it's timestamp, process it and go to sleep, - PF1 requests a timestamp again, - just before PF0 goes to sleep timestamp of PF1 appear, - PF0 finishes all it's timestamps and go to sleep (PF1 also sleeping). That leaves PF1 timestamp memory not read, which lead to blocking the next interrupt from arriving. Fix it by adding auxiliary devices and only one driver to handle all the timestamps for all PF's by PHC owner. In the past each PF requested it's own timestamps and process it from the start till the end which causes problem described above. Currently each PF requests the timestamps as before, but the actual reading of the completed timestamps is being done by the PTP auxiliary driver, which is registered by the PF which owns PHC. Additionally, the newly introduced auxiliary driver/devices for PTP clock owner will be used for other features in all products (including E810). Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com> Signed-off-by: Michal Michalik <michal.michalik@intel.com> Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@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.