On Tue, Jun 04, 2024 at 09:14:00AM -0400, Mateusz Polchlopek wrote: > From: Jacob Keller <[email protected]> > > Add support for receive timestamps to the Rx hotpath. This support only > works when using the flexible descriptor format, so make sure that we > request this format by default if we have receive timestamp support > available in the PTP capabilities. > > In order to report the timestamps to userspace, we need to perform > timestamp extension. The Rx descriptor does actually contain the "40 > bit" timestamp. However, upper 32 bits which contain nanoseconds are > conveniently stored separately in the descriptor. We could extract the > 32bits and lower 8 bits, then perform a bitwise OR to calculate the > 40bit value. This makes no sense, because the timestamp extension > algorithm would simply discard the lower 8 bits anyways. > > Thus, implement timestamp extension as iavf_ptp_extend_32b_timestamp(), > and extract and forward only the 32bits of nominal nanoseconds. > > Signed-off-by: Jacob Keller <[email protected]> > Reviewed-by: Wojciech Drewek <[email protected]> > Reviewed-by: Rahul Rameshbabu <[email protected]> > Reviewed-by: Sunil Goutham <[email protected]> > Signed-off-by: Mateusz Polchlopek <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
