[PATCH v2 3/5] ath10k: drain tx before restarting hw

[Johannes Berg]

On Mon, 2014-05-26 at 07:48 +0200, Michal Kazior wrote:
> On 23 May 2014 15:03, Johannes Berg <johannes at sipsolutions.net> wrote:
> > On Fri, 2014-05-23 at 11:06 +0200, Michal Kazior wrote:
> >
> >> There's nothing wrong with other thread holding it. Actually that's
> >> the reason for this very check.
> >>
> >> The point is to prevent ath10k_drain_tx() being called while caller
> >> (current thread) holds conf_mutex. If it were to hold conf_mutex then
> >> cancel_work_sync() can deadlock as both workers it tries to stop try
> >> to get a hold of the lock too.
> >
> > That seems pointless - lockdep would warn you about that *anyway*
> > because cancel_work_sync() and friends have proper annotations. Try it
> > sometime :)
> 
> Does it splat every time or just by chance or after a deadlock?

Whenever you execute the second path for the first time.

johannes