wake_up_interruptible in ISR

[Jeff Haran]

> -----Original Message-----
> From: Jeff Haran
> Sent: Tuesday, May 26, 2015 10:31 AM
> To: 'Chan Kim'; kernelnewbies at kernelnewbies.org
> Subject: RE: wake_up_interruptible in ISR
> 
> > -----Original Message-----
> > From: kernelnewbies-bounces at kernelnewbies.org
> [mailto:kernelnewbies-
> > bounces at kernelnewbies.org] On Behalf Of Chan Kim
> > Sent: Monday, May 25, 2015 10:23 PM
> > To: kernelnewbies at kernelnewbies.org
> > Subject: wake_up_interruptible in ISR
> >
> >
> >
> > Hello,
> >
> > I see in the source (linux ver 3.3) that wake_up_interruptible
> > function doesn't sleep
>

Please ignore the below. I confused it with wake_event_interruptible().

No enough coffee yet this morning. Sorry for the confusion.

Jeff Haran

> Not sure how you came to that conclusion, but calling that function definitely
> can result in an attempt to do a context switch. That's what the "scheduling
> while atomic" is telling you.
> To my knowledge it is only safe to call this from process context.
> 
> No ISRs, no bottom halves.
> 
> Could be it's that "_interruptible" in the name that is misleading you. That
> means the wait can be interrupted and the call can return if the process
> doing the waiting is delivered a signal. It's got nothing to do with "interrupts"
> per se.
> 
> Jeff Haran
> 
> > so I used in it an ISR but I'm getting 'BUG:scheduling while atomic'
> > message. (I'm not sure it's coming from this) I'm looking for the
> > exact cause but Is there any caveat when using wake_up_interruptible() in
> an ISR?
> > (I found some drivers use it in ISR, some use it in work_struct)
> >
> > I also read in http://www.slideshare.net/rampalliraj/tasklet-vs-work-
> > queues?from_action=save  that tasklet is not allowed to sleep but work is.
> > (because  tasklet is not in process context, but in bottom-half) I
> > don't know if I have to move my wake_up_interruptible function to
> > tasklet or
> > work(queue) or even it matters to the current problem.
> >
> > Any tip will be appreciated.
> > Regards,
> >
> > Chan
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