Messages in this thread | | | Subject | Re: [v1,net-next, 1/2] ethtool: add setting frame preemption of traffic classes | From | Murali Karicheri <> | Date | Tue, 25 Feb 2020 12:55:59 -0500 |
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Hi Vinicius,
On 02/11/2020 02:22 PM, Vinicius Costa Gomes wrote: > Murali Karicheri <m-karicheri2@ti.com> writes: > >> We are still working to send a patch for taprio offload on our hardware >> and it may take a while to get to this. So if someone can help to add >> the required kernel/driver interface for this, that will be great! > > Will add this to my todo list. But if anyone else has the spare cycles > feel free to have a go at it. > Thanks! We have made some progress in sending the base driver to netdev list now https://lkml.org/lkml/2020/2/22/157
This device is taprio offload capable. Next step is to add taprio offload to this driver. Then other features will follow.
>> >>>>> - ConfigChangeError - Error in configuration (AdminBaseTime < >>>>> CurrentTime) >>>> >>>> This can be exported similarly. >>> >>> In my view, having this as a "runtime" error is not useful, as we can >>> verify this at configuration time. >> >> Looks like this is not an error per 802.1Q standard if I understood it >> correctly. >> >> This is what I see. >> ======================================================================= >> From 802.1Q 2018, 8.6.9.1.1 SetCycleStartTime() >> >> If AdminBaseTime is set to the same time in the past in all bridges and >> end stations, OperBaseTime is always in the past, and all cycles start >> synchronized. Using AdminBaseTime in the past is appropriate when you >> can start schedules prior to starting the application that uses the >> schedules. Use of AdminBaseTime in the future is intended to change a >> currently running schedule in all bridges and end stations to a new >> schedule at a future time. Using AdminBaseTime in the future is >> appropriate when schedules must be changed without stopping the >> application >> ======================================================================== >> > > What I meant here is the case that I already have an "oper" schedule > running, so my "oper->base_time" is in the past, and I try to add an > "admin" schedule with a "base_time" also in the past. What's the > expected behavior in this case? The text about stopping/starting > applications doesn't seem to apply to the way the tc subsystem interacts > with the applications. > > I try to add an "admin" schedule with a "base_time" also in the past. > What's the expected behavior in this case?
Ok got it. I don't think this behavior is explained in the spec. I would assume a sane thing to do is to switch to admin schedule if admin->base_time is newer than oper->base_time and flag the ConfigChangeError to be compliant to the spec, but frankly speaking I don't know how application is going to use this. It is a low priority item IMO and can be added as needed.
Regards,
Murali >>> >>>> >>>>> - SupportedListMax - Maximum supported Admin/Open shed list. >>>>> >>>>> Is there a plan to export these from driver through tc show or such >>>>> command? The reason being, there would be applications developed to >>>>> manage configuration/schedule of TSN nodes that would requires these >>>>> information from the node. So would need a support either in tc or >>>>> some other means to retrieve them from hardware or driver. That is my >>>>> understanding... >>>>> >>> >>> Hm, now I understamd what you meant here... >>> >>>> >>>> Not sure what answer you expect to receive for "is there any plan". >>>> You can go ahead and propose something, as long as it is reasonably >>>> useful to have. >>> >>> ... if this is indeed useful, perhaps one way to do is to add a subcommand >>> to TC_SETUP_QDISC_TAPRIO, so we can retrieve the stats/information we want >>> from the driver. Similar to what cls_flower does. >>> >> >> What I understand is that there will be some work done to allow auto >> configuration of TSN nodes from user space and that would need access to >> all or some of the above parameters along with tc command to configure >> the same. May be a open source project for this or some custom >> application? Any such projects existing?? > > Yeah, this is a big missing piece for TSN. I've heard 'netopeer2' and > 'sysrepo' mentioned when similar questions were asked, but I have still > to take a look at them and see what's missing. (Or if they are the right > tool for the job) > >
-- Murali Karicheri Texas Instruments
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