> -----Original Message-----
> From: Hilman, Kevin
> Sent: Thursday, June 16, 2011 11:55 PM
> To: Premi, Sanjeev
> Cc: linux-omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] omap3: pm: Downgrade WARN for no wakeup source
>
> "Premi, Sanjeev" <premi@xxxxxx> writes:
>
> >> -----Original Message-----
> >> From: Hilman, Kevin
> >> Sent: Thursday, June 16, 2011 8:52 PM
> >> To: Premi, Sanjeev
> >> Cc: linux-omap@xxxxxxxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> >> Subject: Re: [PATCH] omap3: pm: Downgrade WARN for no wakeup source
> >>
> >> Hi Sanjeev,
> >>
> >> Sanjeev Premi <premi@xxxxxx> writes:
> >>
> >> > When multiple wakeup sources are defined in a system,
> >> > there is a small window, when more than one source
> >> > can trigger wakeup interrupt.
> >> >
> >> > In the current implementation, the do-while() loop
> >> > can handle all wakeup sources that are recorded when
> >> > probing the status register in prcm_interrupt_handler().
> >> >
> >> > When the ISR executes due to next queued wakeup, it
> >> > there is nothing to be handled and value of "c" is 0.
> >>
> >> Thanks for tracking this one down.
> >>
> >> However, It's still not clear to me what is happening here.
> >>
> >> Why is the IRQ firing if there is nothing to be handled?
> >> That suggests
> >> to me that the IRQ status is not properly being cleared.
> >
> > [SP] On the contrary the IRQ status is actually getting cleared,
> > but there are more than "1" PRCM interrupts queued.
> >
> > The do-while() clears all the interrupt sources that
> > are flagged in the status register.
> >
> > When the next wakeup interrupt is getting processed, the
> > status register doesn't contain any "source" to handle.
>
> Still confused.
>
> If a wakeup interrupt is fired, it was caused by something.
>
> IOW, if "the status register doesn't contain any source", how is
>
> if (irqstatus_mpu & (OMAP3430_WKUP_ST_MASK |
> OMAP3430_IO_ST_MASK))
>
> ever true?
[sp] I had been hesitant to say "nesting" because the wakeup
interrupts seem to be independent of each other. But now
I think - from SW perspective, it should/could be considered
as nesting.
~sanjeev
>
> Kevin
> --
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
