Re: [PATCH 2/5] mwifiex: use spinlock for 'mwifiex_processing' in shutdown_drv

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Amit,

On Wed, Oct 26, 2016 at 03:23:08PM +0000, Amitkumar Karwar wrote:
> 
> This race won't occur. At this point of time(i.e while calling mwifiex_shutdown_drv() in deinit), following things are completed. We don't expect mwifiex_main_process() to be scheduled.
> 1) Connection to peer device is terminated at the beginning of teardown thread. So we don't receive any Tx data from kernel.
> 2) Last command SHUTDOWN is exchanged with firmware. So there won't be any activity/interrupt from firmware.
> 3) Interrupts are disabled.
> 4) "adapter->surprise_removed" flag is set. It will skip mwifiex_main_process() calls.
> 
> -----------
> static void mwifiex_main_work_queue(struct work_struct *work)
> {
>         struct mwifiex_adapter *adapter =
>                 container_of(work, struct mwifiex_adapter, main_work);
> 
>         if (adapter->surprise_removed)
>                 return;
>         mwifiex_main_process(adapter);
> }
> ----------
> 5) We have "mwifiex_terminate_workqueue(adapter)" call to flush and destroy workqueue.

OK, but if interrupts are disabled and you ensure that work is flushed
or completed before you call mwifiex_shutdown_drv() then I do not
understand why you need all of this at all? Why do you need to check
status in mwifiex_shutdown_drv() and why do you want
mwifiex_main_process() to call mwifiex_shutdown_drv() in certain cases?
Can you simply remove all this stuff?

Thanks.

-- 
Dmitry