Re: [PATCH net-next v7 15/16] net: ethtool: ts: Let the active time stamping layer be selectable

[Vladimir Oltean]

On Wed, Nov 22, 2023 at 04:08:50PM +0200, Vladimir Oltean wrote:
> The concept of an "active phc_index" would not explicitly exist in the
> UAPI. Thus I'm not sure what's with this TSINFO_SET being floated around.
> The only thing would exist is a configurable rx_filter and tx_type per
> hwtstamp provider (aka "{phc_index, qualifier}"). User space will have
> to learn to select the hwtstamp provider it wants to configure through
> netlink, and use for its class of traffic.

@Jakub, for your long-term "MAC timestamps for PTP, DMA for everything else".
How do you see this? I guess we need some sort of priority function in
the UAPI between hwtstamp providers.

And even with that, I think the enums that we currently have for filters
are not specific enough. The most we could expose is:

                      MAC provider                      DMA provider

hwtstamp_rx_filters   HWTSTAMP_FILTER_PTP_V2_EVENT      HWTSTAMP_FILTER_ALL
tx_type               HWTSTAMP_TX_ON                    HWTSTAMP_TX_ON

but it isn't clear: for PTP, does the DMA provider give you an RX
timestamp too? What about a TX timestamp?