[Intel-wired-lan] [PATCH net] ice: Fix race condition during interface enslave

[Ivan Vecera <ivecera@redhat.com>]

On Thu, 10 Mar 2022 17:48:16 +0000
"Ertman, David M" <david.m.ertman@intel.com> wrote:

> This only addresses one case of unplugging the auxiliary bus.  Rather than controlling one instance of
> calling ice_unplig_aux_dev(), it seems like it would be better to modify ice_unplug_aux_dev so that it
> will pause until any plugging is done by the service task (check for the pf->flag bit and wait until it clears
> before progressing).

You cannot wait in ice_unplug_aux_dev() for ICE_FLAG_PLUG_AUX_DEV to be cleared because
ice_clear_rdma_cap() is called under RTNL.
This patch is a counter part for commit 5dbbbd01cbba83 ("ice: Avoid RTNL lock when
re-creating auxiliary device") that eliminates ice_plug_aux() and fixed first part
of deadlock and this patch fixes a second part and eliminates also ice_unplug_aux_dev()
to be called under RTNL.

Thanks,
Ivan