Re: [PATCH net-next] net: mana: Cache MANA_QUERY_LINK_CONFIG result to avoid repeated HWC queries

[Erni Sri Satya Vennela]

On Fri, Jun 05, 2026 at 04:13:15PM -0700, Jakub Kicinski wrote:
> On Thu, 4 Jun 2026 22:29:29 -0700 Erni Sri Satya Vennela wrote:
> > I tried two netdev_lock-based variants. 
> > 
> > mana_query_link_cfg() has four callers:
> > 
> > 1 ethtool ioctl/netlink			- has RTNL	- has netdev->lock
> > 2 sysfs speed_show/duplex_show		- has RTNL	- no netdev->lock
> > 3 netvsc_get_link_ksettings VF forward	- has RTNL	- no netdev->lock
> > 4 mana_shaper_set			- no RTNL	- has netdev->lock
> > 
> > No existing lock covers all four.
> 
> How fresh is your tree? The just-minted commit 9f275c2e9020 should
> address the gap, I believe?

Hi Jakub,

Thanks for pointing out the commit 9f275c2e9020. It does close the gap.
My analysis was against a tree that predated it but the commit landed
on net-next on Jun 4 21:30 UTC and my reply went out about an hour later,
so the rebase that picked it up hadn't happened on my end yet.

I've now rebased to current net-next and re-walked the four callers of
mana_query_link_cfg(). All of them hold netdev->lock by the time they 
reach mana_query_link_cfg(), and the race scenarios I described no longer
apply.

Thanks,
Vennela