[PATCH] irq: always set IRQF_ONESHOT if no primary handler is specified

[Paul Walmsley]

On Thu, 18 Aug 2011, Pantelis Antoniou wrote:

> Let me report that with this change Beagle board fails to boot,
> hangs right on rootfs mount.

Confirmed here.

Commit f3637a5f2e2eb391ff5757bc83fb5de8f9726464 ("irq: Always set 
IRQF_ONESHOT if no primary handler is specified"), merged as part of 
v3.1-rc3, won't boot into userspace via MMC on either OMAP4 Panda or 
OMAP3530 BeagleBoard.  v3.1-rc2 works.


- Paul

> Users of BB should revert this until the offending driver(s) are fixed.
> 
> Regards
> 
> -- Pantelis
> 
> On Jul 7, 2011, at 11:32 PM, Sebastian Andrzej Siewior wrote:
> 
> > If no primary handler is specified then a default one is assigned which
> > always returns IRQ_WAKE_THREAD. This handler requires the IRQF_ONESHOT
> > flag on LEVEL / EIO typed irqs because the source of interrupt is not
> > disabled.
> > Since it is required for those users and there is no difference for others
> > it makes sense to add this flag unconditionally.
> > 
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
> > ---
> > A quick grep shows that drivers/staging/iio/adc/ad7816.c is the only
> > driver in tree doing it wrong i.e. request_threaded_irq with
> > IRQF_TRIGGER_{LOW|HIGH} but without ONEHOST.
> > 
> > There are 59 users in tree which request an edge typed interrupt. 24 of
> > them specify the ONEHOST flag the others don't. Both variants are valid
> > and identical but a consistent behavior would be nice.
> > 
> > There is a total of 134 users and 87 specify the irq type directly. For
> > the remaining 47 the type depends on initial configuration of the irq chip
> > or it might be specified via the device tree, dunno. 
> > Should that patch be accepted I suggest to remove the ONESHOT flag from
> > every request_th.* which uses NULL as the primary handler so we have a
> > consistent behavior here.
> > 
> > kernel/irq/manage.c |    1 +
> > 1 files changed, 1 insertions(+), 0 deletions(-)
> > 
> > diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> > index 0a7840ae..3f9cd47 100644
> > --- a/kernel/irq/manage.c
> > +++ b/kernel/irq/manage.c
> > @@ -1322,6 +1322,7 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
> > 		if (!thread_fn)
> > 			return -EINVAL;
> > 		handler = irq_default_primary_handler;
> > +		irqflags |= IRQF_ONESHOT;
> > 	}
> > 
> > 	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
> > -- 
> > 1.7.4.4
> > 
> > --
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