> -----Original Message----- > From: Dmitry Torokhov [mailto:dmitry.torokhov@xxxxxxxxx] > Sent: 2016年11月4日 2:49 > To: Brian Norris > Cc: Xinming Hu; Amitkumar Karwar; linux-wireless@xxxxxxxxxxxxxxx; Cathy Luo; > Nishant Sarmukadam; rajatja@xxxxxxxxxx > Subject: Re: [PATCH v2 2/5] mwifiex: use spinlock for 'mwifiex_processing' in > shutdown_drv > > On Thu, Nov 3, 2016 at 12:27 PM, Brian Norris <briannorris@xxxxxxxxxxxx> > wrote: > > On Thu, Nov 03, 2016 at 09:15:04AM -0700, Dmitry Torokhov wrote: > >> On Thu, Nov 03, 2016 at 08:34:06AM +0000, Xinming Hu wrote: > >> > > -----Original Message----- > >> > > From: linux-wireless-owner@xxxxxxxxxxxxxxx > >> > > [mailto:linux-wireless-owner@xxxxxxxxxxxxxxx] On Behalf Of Dmitry > >> > > Torokhov > >> > > > >> > > Instead please remove call to mwifiex_shutdown_drv() in the main > >> > > routine and "if (adapter->mwifiex_processing)" check here. > >> > > > >> > > >> > mwifiex_main_process will be used from interrupt or workqueue. > >> > Now we have disabled interrupt and flush workqueue, so > >> > mwifiex_main_process won't be scheduled in the future. > >> > But mwifiex_main_process might just running in context of last > >> > interrupt, so we need wait current main_process complete in > >> > mwifiex_shutdown_drv. > >> > >> synchronize_irq() is your friend then. > > > > Hmm, that sounds right, but IIUC, the "interrupt context" is actually > > only used for SDIO, and for SDIO, the driver doesn't actually have > > access to the IRQ number. The MMC/SDIO layer has some extra > > abstraction around the IRQ. So this may be more difficult than it appears. > > > > Do we need a sdio_synchronize_irq() API? > > Actually the ->disable_irq() method should be responsible for making sure it > does not complete while interrupt handler is running. As far as I can see, for > SDIO case, we end up calling sdio_card_irq_put() which stops kernel thread > and won't return while the thread is running. For other interfaces we need to > check. IIRC USB lacks > ->disable_irq() altogether and this is something that shoudl be fixed > (by doing usb_kill_urb() at the minimum). > Thanks for the explain, will keep this cleanup work. > Thanks. > > -- > Dmitry Regards, Xinming
