Hi Brian/Dmitry,
> From: Brian Norris [mailto:[email protected]]
> Sent: Tuesday, October 25, 2016 5:26 AM
> To: Dmitry Torokhov
> Cc: Amitkumar Karwar; [email protected]; Cathy Luo; Nishant
> Sarmukadam; [email protected]
> Subject: Re: [PATCH 2/5] mwifiex: use spinlock for 'mwifiex_processing'
> in shutdown_drv
>
> Hi,
>
> On Mon, Oct 24, 2016 at 04:47:20PM -0700, Dmitry Torokhov wrote:
> > On Mon, Oct 24, 2016 at 07:51:29PM +0530, Amitkumar Karwar wrote:
> > > This variable is guarded by spinlock at all other places. This patch
> > > takes care of missing spinlock usage in mwifiex_shutdown_drv().
> > >
> > > Signed-off-by: Amitkumar Karwar <[email protected]>
> > > ---
> > > drivers/net/wireless/marvell/mwifiex/init.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/net/wireless/marvell/mwifiex/init.c
> > > b/drivers/net/wireless/marvell/mwifiex/init.c
> > > index 82839d9..8e5e424 100644
> > > --- a/drivers/net/wireless/marvell/mwifiex/init.c
> > > +++ b/drivers/net/wireless/marvell/mwifiex/init.c
> > > @@ -670,11 +670,14 @@ mwifiex_shutdown_drv(struct mwifiex_adapter
> > > *adapter)
> > >
> > > adapter->hw_status = MWIFIEX_HW_STATUS_CLOSING;
> > > /* wait for mwifiex_process to complete */
> > > + spin_lock_irqsave(&adapter->main_proc_lock, flags);
> > > if (adapter->mwifiex_processing) {
> > > + spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
> > > mwifiex_dbg(adapter, WARN,
> > > "main process is still running\n");
> > > return ret;
> > > }
> > > + spin_unlock_irqrestore(&adapter->main_proc_lock, flags);
> >
> > What happens if adapter->mwifiex_processing will become true here?
>
> That's why I commented:
>
> "I'm not quite sure why we have this check in the first place; if the
> main process is still running, then don't we have bigger problems here
> anyway?"
If mwifiex_processing is true here, it means main_process is still running. We
have set "adapter->hw_status = MWIFIEX_HW_STATUS_CLOSING" in
mwifiex_shutdown_drv().
Now we will wait until main_process() gets completed.
---------------------
if (mwifiex_shutdown_drv(adapter) == -EINPROGRESS)
wait_event_interruptible(adapter->init_wait_q,
adapter->init_wait_q_woken);
--------------
We have following logic at the end of main_process()
-------
exit_main_proc:
if (adapter->hw_status == MWIFIEX_HW_STATUS_CLOSING)
mwifiex_shutdown_drv(adapter);
--------
Regards,
Amitkumar Karwar
