RE: [PATCH 2/8] ethdev: add dev op for IP reassembly configuration

[Akhil Goyal <gakhil@marvell.com>]

Hi Konstantin,

> > > > > > Another question - if we have reassembly_conf_set() would it make
> sense
> > to
> > > > > > have also reassembly_conf_get?
> > > > > > So user can retrieve current ip_reassembly config values?
> > > > > >
> > > > > The set/supported values can be retrieved using rte_eth_dev_info ::
> > > > reass_capa
> > > >
> > > > Hmm, I thought rte_eth_dev_info :: reass_capa reports
> > > > max supported values, not currently set values.
> > > > Did I misunderstand something?
> > > >
> > > Reassembly configuration is expected to be a one-time setting and is not
> > expected
> > > to change multiple times in the application.
> > > You are correct that rte_eth_dev_info :: reass_capa reports max supported
> > values
> > > by the PMD.
> > > But if somebody uses the _set API, dev_info values will be overwritten.
> > > However, a get API can be added, if we have some use case.
> > > IMO, we can add it later if it will be required.
> >
> > Basically you forbid user to reconfigure this feature
> > during application life-time?
> > That sounds like a really strange approach to me and
> > Probably will affect its usability in a negative way.
> > Wonder why it has to be that restrictive?
> > Also with the model you suggest, what would happen after user will do:
> > dev_stop(); dev_configure();?
> > Would rte_eth_dev_info :: reass_capa be reset to initial values,
> > or user values will be preserved, or ...?
> >
> I am not restricting the user to not reconfigure the feature.
> When dev_configure() is called again after dev_stop(), it will reset the previously
> set values to max ones.
> However, if you insist the get API can be added. No strong opinion on that.

On another thought, setting dev_info :: reass_capa to a max value and not changing it
in reassembly_conf_set() will make more sense.
The most common case, would be to get the max values and if they are not good
Enough for the application, set lesser values using the new API.
I do not see a use case to get the current values set. However, it may be used for debugging
some driver issue related to these values. But, I believe that can be managed internally
in the PMD. Do you suspect any other use case for get API?