Re: [LKP] [x86/platform, acpi] 7486341a98f: genirq: Flags mismatch irq 8. 00000080 (mmc0) vs. 00000000 (rtc0)

From: Li, Aubrey
Date: Mon Mar 30 2015 - 04:28:12 EST


This is a multi-part message in MIME format.Ying,

can you please try this patch to see if the problem is gone on your side?

Thanks,
-Aubrey


On 2015/3/26 20:13, Li, Aubrey wrote:
> On 2015/3/25 15:22, Huang Ying wrote:
>> [ 28.745155] genirq: Flags mismatch irq 8. 00000080 (mmc0) vs. 00000000 (rtc0)
>
> okay, I replicated this on my side now.
>
> Firstly, I don't think the patch did anything wrong. However, the patch
> exposes a few issues FWICT currently:
>
> - Should we enable RTC Alarm the kind of Fixed hardware event in
> hardware-reduced ACPI mode? I found RTC required registers in ACPI PM
> block are not valid(register address = 0)
>
> - I checked RTC device in ACPI table, there is no interrupt resource
> under RTC(firmware bug?), So irq 8 should be a hardcoded number. The
> question is, shouldn't we update bitmap of allocated_irqs here? Or we
> assume irq0~15 is reserved? If we assume IRQ0~15 is reserved, then
> requesting IRQ8 without updating bitmap of allocated_irqs is fine.
>
> - Because we don't update bitmap of allocated_irqs when RTC request
> IRQ8, so when MMC driver allocate irq resource, it's possible it gets
> irq8, so we saw "genirq: Flags mismatch irq 8. 00000080 (mmc0) vs.
> 00000000 (rtc0)". So here is another question, when we dynamically
> allocate irq from irq domain, shouldn't we start from IRQ16? Yes, if
> allocated_irqs bitmap is updated, then it should be fine if we start
> from IRQ1.
>
> What the patch does is, it changes the behavior of how we allocate irq
> from irq domain. Previously we have legacy IRQs so we statically assign
> IRQ numbers for IOAPICs to host legacy IRQs, and now we allocate every
> IRQ dynamically.
>
> For me I think I can deliver a patch against RTC driver to update
> allocated_irqs bitmap, also, we should free irq when we found RTC ACPI
> registers are not valid.
>
> Certainly I'm open to any suggestions.
>
> Thanks,
> -Aubrey
>