Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: common_interrupt: No irq handler for vector | Date | Mon, 14 Dec 2020 21:50:38 +0100 |
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On Mon, Dec 14 2020 at 21:41, Thomas Gleixner wrote: > On Mon, Dec 14 2020 at 09:11, Shuah Khan wrote: >> On 12/12/20 12:33 PM, Thomas Gleixner wrote: >>> On Fri, Dec 11 2020 at 13:41, Shuah Khan wrote: >>> >>>> I am debugging __common_interrupt: 1.55 No irq handler for vector >>>> messages and noticed comments and code don't agree: >>> >>> I bet that's on an AMD system with broken AGESA BIOS.... Good luck >>> debugging it :) BIOS updates are on the way so I'm told. >>> >> Interesting. The behavior I am seeing doesn't seem to be consistent >> with BIOS problem. I don't see these messages on 5.10-rc7. I started >> seeing them on stable releases. It started right around 5.9.9 and >> not present on 5.9.7. > > What kind of machine? > >> I am bisecting to isolate. Same issue on all stables 5.4, 4.19 and >> so on. If it is BIOS problem I would expect to see it on 5.10-rc7 >> and wouldn't have expected to start seeing it 5.9.9. > > Can you provide some more details, e.g. dmesg please? > >>> No. It's perfectly correct in the MSI code. See further down. >>> >>> if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector]))) >>> this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED); >>> >> >> I am asking about inconsistent comments and the actual message as the >> comment implies if vector is VECTOR_UNUSED state, this message won't >> be triggered in common_interrupt. Based on that my read is the comment >> might be wrong if the code is correct as you are saying. > > The comment says: > > >> * anyway. If the vector is unused, then it is marked so it won't > >> * trigger the 'No irq handler for vector' warning in > >> * common_interrupt(). > > If the vector is unused, then it is _marked_ so .... > > It perhaps should explicitely say 'is marked as VECTOR_RETRIGGERED' to make > it clear.
And it's only marked for this particular case to prevent the message from being shown. Because the insanities we need to do to migrate unmaskable (*sigh*) MSI interrupts can trigger that warning which would be just wrong and confusing. You warning is _not_ coming from a broken MSI migration attempt, believe me.
Thanks,
tglx
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