Hi Vladimir,

On 01/23/2020 08:30 AM, Vladimir Oltean wrote:

Hi Murali,

On Wed, 22 Jan 2020 at 20:04, Murali Karicheri [off-list ref] wrote:

quoted

I have question about the below parameters in The Gate Parameter Table
that are not currently supported by tc command. Looks like they need to
be shown to user for management.

      - ConfigChange - Looks like this needs to be controlled by
        user. After sending admin command, user send this trigger to start
        copying admin schedule to operation schedule. Is this getting
        added to tc command?

"The ConfigChange parameter signals the start of a
configuration change for the gate
when it is set to TRUE. This should only be done
when the various administrative parameters
are all set to appropriate values."

As far as my understanding goes, all tc-taprio commands currently
behave as though this boolean is implicitly set to TRUE after the
structures have been set up. I'm not sure there is any value in doing
otherwise.

That is my understanding as well. However I found this in the 802.1Q
and want to see if someone has insight into this parameter. So perhaps
we can ignore this for now and re-visit when there is a real need for
the same.

quoted

      - ConfigChangeTime - The time at which the administrative variables
        that determine the cycle are to be copied across to the
        corresponding operational variables, expressed as a PTP timescale

This is the base-time of the admin schedule, no?

I think there is cycle time extension possible and in that case,
ConfigChangeTime may be different from Admin  base-time. So this gives
the actual time when the cycle configuration is actually applied.

"The PTPtime at which the next config change is scheduled to occur.
The value is a representation of a PTPtime value,
consisting of a 48-bit integer
number of seconds and a 32-bit integer number of nanoseconds."

quoted

      - TickGranularity - the management parameters specified in Gate
        Parameter Table allow a management station to discover the
        characteristics of an implementation’s cycle timer clock
        (TickGranularity) and to set the parameters for the gating cycle
        accordingly.

Not sure who is going to use this and for what purpose, but ok.

Same here. Not sure how this will be used by application.

quoted

      - ConfigPending - A Boolean variable, set TRUE to indicate that
        there is a new cycle configuration awaiting installation.

I had tried to export something like this (driver calls back into
sch_taprio.c when hw has applied the config, this would result in
ConfigPending = FALSE), but ultimately didn't finish the idea, and it
caused some problems too, due to incorrect RCU usage.

Ok. Hope you plan to send a patch for this in the future.

quoted

      - ConfigChangeError - Error in configuration (AdminBaseTime <
        CurrentTime)

This can be exported similarly.

Ok.

quoted

      - 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...

Not sure what answer you expect to receive for "is there any plan".

To avoid duplicating the work if someone is already working on this.

You can go ahead and propose something, as long as it is reasonably
useful to have.

Ok. Will keep in mind.

quoted

Regards,

Murali

--
Murali Karicheri
Texas Instruments

Thanks,
-Vladimir

-- 
Murali Karicheri
Texas Instruments