Messages in this thread | | | Date | Thu, 28 Jan 2016 09:59:56 +0000 | From | Brian Starkey <> | Subject | Re: [PATCH] genirq: fix trigger flags check for shared irqs |
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Hi Thomas,
Thanks for taking a look at this.
On Tue, Jan 26, 2016 at 09:45:32PM +0100, Thomas Gleixner wrote: >On Tue, 26 Jan 2016, Brian Starkey wrote: > >> For shared interrupts, if one requester passes in any IRQF_TRIGGER_* >> flags whilst another doesn't, __setup_irq() can erroneously fail. >> >> The no-flags case should be treated as "already configured", so change >> __setup_irq() to only check that the flags match if any have been >> provided. > >What happens if that "already configured", i.e. the default setting, is >conflicting with the newly requested interrupt? > >I rather prefer the failure than the resulting silent wreckage. >
Yes, I agree that would be best avoided. It seems to me that this case is actually handled a bit lower down:
} else if (new->flags & IRQF_TRIGGER_MASK) { unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK; unsigned int omsk = irq_settings_get_trigger_mask(desc);
if (nmsk != omsk) /* hope the handler works with current trigger mode */ pr_warning("irq %d uses trigger mode %u; requested %u\n", irq, nmsk, omsk); }
Perhaps that should be louder/fatal?
Best regards,
-Brian
>Thanks, > > tglx >
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