Re: [PATCH v2 3/3] driver core: Skip unnecessary work when device doesn't have sync_state()

[Davide Caratti <dcaratti@redhat.com>]

On Wed, 2020-03-25 at 08:44 +0100, Greg Kroah-Hartman wrote:
> On Tue, Mar 24, 2020 at 09:03:28PM +0100, Davide Caratti wrote:
> > On Fri, 2020-02-21 at 00:05 -0800, Saravana Kannan wrote:
> > > A bunch of busy work is done for devices that don't have sync_state()
> > > support. Stop doing the busy work.
> > > 
> > > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > > ---
> > >  drivers/base/core.c | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > 
> > hello Greg,
> > 
> > this patch and patch 2/3 of the same series proved to fix systematic
> > crashes (NULL pointer dereference in device_links_flush_sync_list() while
> > loading mac80211_hwsim.ko, see [1]) on Fedora 31, that are triggered by
> > NetworkManager-ci [2]. May I ask to queue these two patches for the next
> > 5.5 stable?
> 
> What are the git commit ids of these patches in Linus's tree that you
> want backported?

right, I should have mentioned them also here: 

ac338acf514e "(driver core: Add dev_has_sync_state())" <-- patch 2/3 
77036165d8bc "(driver core: Skip unnecessary work when device doesn't have sync_state())" <-- patch 3/3

like Saravana mentioned, the problem is probably introduced by patch
1/3 of the series, 

77036165d8bc "(driver core: Skip unnecessary work when device doesn't have sync_state())"

that's already in stable 5.5.

thanks!
-- 
davide