RE: [EXT] Re: [PATCH net-next 4/4] qed: Add devlink support for configuration attributes.

[Sudarsana Reddy Kalluru <skalluru@marvell.com>]

> -----Original Message-----
> From: Jiri Pirko <jiri@resnulli.us>
> Sent: Thursday, June 20, 2019 7:08 PM
> To: Sudarsana Reddy Kalluru <skalluru@marvell.com>
> Cc: Jakub Kicinski <jakub.kicinski@netronome.com>; davem@davemloft.net;
> netdev@vger.kernel.org; Michal Kalderon <mkalderon@marvell.com>; Ariel
> Elior <aelior@marvell.com>
> Subject: Re: [EXT] Re: [PATCH net-next 4/4] qed: Add devlink support for
> configuration attributes.
> 
> Thu, Jun 20, 2019 at 02:09:29PM CEST, skalluru@marvell.com wrote:
> >> -----Original Message-----
> >> From: Jakub Kicinski <jakub.kicinski@netronome.com>
> >> Sent: Tuesday, June 18, 2019 4:24 AM
> >> To: Sudarsana Reddy Kalluru <skalluru@marvell.com>
> >> Cc: davem@davemloft.net; netdev@vger.kernel.org; Michal Kalderon
> >> <mkalderon@marvell.com>; Ariel Elior <aelior@marvell.com>; Jiri Pirko
> >> <jiri@resnulli.us>
> >> Subject: [EXT] Re: [PATCH net-next 4/4] qed: Add devlink support for
> >> configuration attributes.
> >>
> >> External Email
> >>
> >> ---------------------------------------------------------------------
> >> - On Mon, 17 Jun 2019 04:45:28 -0700, Sudarsana Reddy Kalluru wrote:
> >> > This patch adds implementation for devlink callbacks for reading/
> >> > configuring the device attributes.
> >> >
> >> > Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
> >> > Signed-off-by: Ariel Elior <aelior@marvell.com>
> >>
> >> You need to provide documentation for your parameters, plus some of
> >> them look like they should potentially be port params, not device params.
> >
> >Thanks a lot for your review. Will add the required documentation. In case
> of Marvell adapter, any of the device/adapter/port parameters can be
> read/configurable via any PF (ethdev) on the port. Hence adding the
> commands at device level. Hope this is fine.
> 
> No it is not. Port param should be port param.
> 
> Also please be careful not to add any generic param as driver specific.
> 
> Thanks!
Hi,
   Could you please with my query on the devlink-port-params implementation. [had sent the same query earlier to jiri@mellanox.com (based on the copyright info)].

Kernel seem to be invoking the driver devlink callbacks (registered via DEVLINK_PARAM_DRIVER) only when the associated parameter is published via devlink_params_publish(). callnback invocation path,
   devlink_nl_param_fill()
   {
                if (!param_item->published)
                         continue;
                 ctx.cmode = i;
                  err = devlink_param_get(devlink, param, &ctx);
   }
The API devlink_params_publish() publishes only the devlink-dev parameters (i.e., registered via devlink_params_register()), not the devlink-port params which are registered via devlink_port_params_register(). I couldn't find any other interface for publishing the devlink-port-params.
I have manually verified setting the published flag for port-params (as in below) and, observed that kernel correctly invokes the callbacks of devlink-port-params.
       list_for_each_entry(param_item, &dl_port.param_list, list) {
                param_item->published = true;
      }
Please let me know if I'm missing something here or, it's a missing functionality in the kernel.

Thanks,
Sudarsana