On Wed, 2 Dec 2020 20:21:01 -0800 Saeed Mahameed wrote: > Add TX PTP port object support for better TX timestamping accuracy. > Currently, driver supports CQE based TX port timestamp. Device > also offers TX port timestamp, which has less jitter and better > reflects the actual time of a packet's transmit.
How much better is it? Is the new implementation is standard compliant or just a "better guess"? > Define new driver layout called ptpsq, on which driver will create > SQs that will support TX port timestamp for their transmitted packets. > Driver to identify PTP TX skbs and steer them to these dedicated SQs > as part of the select queue ndo. > > Driver to hold ptpsq per TC and report them at > netif_set_real_num_tx_queues(). > > Add support for all needed functionality in order to xmit and poll > completions received via ptpsq. > > Add ptpsq to the TX reporter recover, diagnose and dump methods. > > Creation of ptpsqs is disabled by default, and can be enabled via > tx_port_ts private flag. This flag is pretty bad user experience. > This patch steer all timestamp related packets to a ptpsq, but it > does not open the port timestamp support for it. The support will > be added in the following patch. Overall I'm a little shocked by this, let me sleep on it :) More info on the trade offs and considerations which led to the implementation would be useful.
