> -----Original Message----- > From: Jakub Kicinski <kuba@xxxxxxxxxx> > Sent: Monday, September 6, 2021 8:39 PM > To: Machnikowski, Maciej <maciej.machnikowski@xxxxxxxxx> > Subject: Re: [PATCH net-next 1/2] rtnetlink: Add new RTM_GETEECSTATE > message to get SyncE status > > On Mon, 6 Sep 2021 18:30:40 +0000 Machnikowski, Maciej wrote: > > > -----Original Message----- > > > From: Jakub Kicinski <kuba@xxxxxxxxxx> > > > Sent: Saturday, September 4, 2021 12:14 AM > > > Subject: Re: [PATCH net-next 1/2] rtnetlink: Add new RTM_GETEECSTATE > > > message to get SyncE status > > > > > > On Fri, 3 Sep 2021 17:14:35 +0200 Maciej Machnikowski wrote: > > > > This patch series introduces basic interface for reading the Ethernet > > > > Equipment Clock (EEC) state on a SyncE capable device. This state gives > > > > information about the state of EEC. This interface is required to > > > > implement Synchronization Status Messaging on upper layers. > > > > > > > > Initial implementation returns SyncE EEC state and flags attributes. > > > > The only flag currently implemented is the EEC_SRC_PORT. When it's > set > > > > the EEC is synchronized to the recovered clock recovered from the > > > > current port. > > > > > > > > SyncE EEC state read needs to be implemented as a ndo_get_eec_state > > > > function. > > > > > > > > Signed-off-by: Maciej Machnikowski > <maciej.machnikowski@xxxxxxxxx> > > > > > > Since we're talking SyncE-only now my intuition would be to put this > > > op in ethtool. Was there a reason ethtool was not chosen? If not what > > > do others think / if yes can the reason be included in the commit > > > message? > > > > Hmm. Main reason for netlink is that linuxptp already supports it, > > and it was suggested by Richard. > > Having an NDO would also make it easier to add a SyncE-related > > files to the sysfs for easier operation (following the ideas from the ptp > > pins subsystem). > > But I'm open for suggestions. > > I think linuxptp will need support for ethtool netlink sockets sooner > rather than later. Moving this to ethtool makes sense to me since it's > very much a Ethernet-oriented API at this point. Ethtool also makes a lot of sense, but will it be possible to still make sysfs, and it makes sense to add it for some deployments (more on that below) > > > > +#define EEC_SRC_PORT (1 << 0) /* recovered clock from the > > > port is > > > > + * currently the source for the EEC > > > > + */ > > > > > > Why include it then? Just leave the value out and if the attr is not > > > present user space should assume the source is port. > > > > This bit has a different meaning. If it's set the port in question > > is a frequency source for the multiport device, if it's cleared - some other > > source is used as a source. This is needed to prevent setting invalid > > configurations in the PHY (like setting the frequency source as a Master > > in AN) or sending invalid messages. If the port is a frequency source > > it must always send back QL-DNU messages to prevent synchronization > > loops. > > Ah! I see. Is being the "source" negotiated somehow? Don't we need to > give the user / linuxptp to select the source based on whatever info > it has about topology? The frequency source can be either pre-set statically, negotiated using ESMC QL-levels (if working in QL-Enabled mode), or follow automatic fallback inside the device. This flag gives feedback about the validity of recovered clock coming from a given port and is useful when you enable multiple recovered clocks on more than one port in active-passive model. In that case the "driving" port may change dynamically, so it's a good idea to have some interface to reflect that. That's where sysfs file be useful. When I add the implementation for recovered clock configuration, the sysfs may be used as standalone interface for configuring them when no dynamic change is needed. > > > or don't check the ifindex at all and let dev_get_by.. fail. > > > > > > > > > Thanks for pushing this API forward! > > > > Addressed all other comments - and thanks for giving a lot of helpful > > suggestions! > > Thanks, BTW I think I forgot to ask for documentation, dumping info > about the API and context under Documentation/ would be great! Could you suggest where to add that? Grepping for ndo_ don't give much. I can add a new synce.rst file if it makes sense.
