Re: [RFC PATCH] net: devlink: devlink_nl_info_fill: populate default information

On Wed, 23 Nov 2022 18:42:41 +0900 Vincent MAILHOL wrote:

I see three solutions:

1/ Do it in the core, clean up all drivers using
devlink_info_driver_name_put() and make the function static (i.e.
forbid the drivers to set the driver name themselves).
N.B. This first solution does not work for
devlink_info_serial_number_put() because the core will not always be
able to provide a default value (e.g. my code only covers USB
devices).

2/ Keep track of which attribute is already set (as you suggested).

3/ Do a function devlink_nl_info_fill_default() and let the drivers
choose to either call that function or set the attributes themselves.

I would tend to go with a mix of 1/ and 2/.

I think 2/ is best because it will generalize to serial numbers while
1/ will likely not. 3/ is a smaller gain.

Jiri already plumbed thru the struct devlink_info_req which is on the
stack of the caller, per request, so we can add the bool / bitmap for
already reported items there quite easily.