Re: False positive "do_IRQ: #.55 No irq handler for vector" messages on AMD ryzen based laptops

[Hans de Goede]

Hi,

On 19-02-19 22:47, Lendacky, Thomas wrote:
> On 2/19/19 3:01 PM, Thomas Gleixner wrote:
> > Hans,
> >
> > On Tue, 19 Feb 2019, Hans de Goede wrote:
> >
> > Cc+: ACPI/AMD folks
> >
> > > Various people are reporting false positive "do_IRQ: #.55 No irq handler for
> > > vector"
> > > messages on AMD ryzen based laptops, see e.g.:
> > >
> > > https://bugzilla.redhat.com/show_bug.cgi?id=1551605
> > >
> > > Which contains this dmesg snippet:
> > >
> > > Feb 07 20:14:29 localhost.localdomain kernel: smp: Bringing up secondary CPUs
> > > ...
> > > Feb 07 20:14:29 localhost.localdomain kernel: x86: Booting SMP configuration:
> > > Feb 07 20:14:29 localhost.localdomain kernel: .... node  #0, CPUs:      #1
> > > Feb 07 20:14:29 localhost.localdomain kernel: do_IRQ: 1.55 No irq handler for
> > > vector
> > > Feb 07 20:14:29 localhost.localdomain kernel:  #2
> > > Feb 07 20:14:29 localhost.localdomain kernel: do_IRQ: 2.55 No irq handler for
> > > vector
> > > Feb 07 20:14:29 localhost.localdomain kernel:  #3
> > > Feb 07 20:14:29 localhost.localdomain kernel: do_IRQ: 3.55 No irq handler for
> > > vector
> > > Feb 07 20:14:29 localhost.localdomain kernel: smp: Brought up 1 node, 4 CPUs
> > > Feb 07 20:14:29 localhost.localdomain kernel: smpboot: Max logical packages: 1
> > > Feb 07 20:14:29 localhost.localdomain kernel: smpboot: Total of 4 processors
> > > activated (15968.49 BogoMIPS)
> > >
> > > It seems that we get an IRQ for each CPU as we bring it online,
> > > which feels to me like it is some sorta false-positive.
> >
> > Sigh, that looks like BIOS value add again.
> >
> > It's not a false positive. Something _IS_ sending a vector 55 to these CPUs
> > for whatever reason.
>
> I remember seeing something like this in the past and it turned out to be
> a BIOS issue.  BIOS was enabling the APs to interact with the legacy 8259
> interrupt controller when only the BSP should. During POST the APs were
> exposed to ExtINT/INTR events as a result of the mis-configuration
> (probably due to a UEFI timer-tick using the 8259) and this left a pending
> ExtINT/INTR interrupt latched on the APs.
>
> When the APs were started by the OS, the latched ExtINT/INTR interrupt is
> processed shortly after the OS enables interrupts. The AP then queries the
> 8259 to identify the vector number (which is the value of the 8259's ICW2
> register + the IRQ level). The master 8259's ICW2 was set to 0x30 and,
> since no interrupts are actually pending, the 8259 will respond with IRQ7
> (spurious interrupt) yielding a vector of 0x37 or 55.
>
> The OS was not expecting vector 55 and printed the message.
>
>  From the Intel Developer's Manual: Vol 3a, Section 10.5.1:
> "Only one processor in the system should have an LVT entry configured to
> use the ExtINT delivery mode."
>
> Not saying this is the problem, but very well could be.

That sounds like a likely candidate, esp. also since this only happens
once per CPU when we first only the CPU.

Can you provide me with a patch with some printk-s / pr_debugs to
test for this, then I can build a kernel with that patch added and
we can see if your hypothesis is right.

Regards,

Hans


> Thanks,
> Tom
>
> > > I temporarily have access to a loaner laptop for a couple of weeks which shows
> > > the same errors and I would like to fix this, but I don't really know how to
> > > fix this.
> >
> > Can you please enable CONFIG_GENERIC_IRQ_DEBUGFS and dig in the files there
> > whether vector 55 is used on CPU0 and which device is associated to that.
> >
> > I bet its a legacy IRQ and as that space starts at 48 (IRQ0) this should be
> > IRQ9 which is usually - DRUMROLL - the ACPI interrupt.
> >
> > The kernel clearly sets that up to be delivered to CPU 0 only, but I've
> > seen that before that the BIOS value add thinks that this setup is not
> > relevant.
> >
> > /me goes off and sings LALALA
> >
> > > Note if you want I can set up root ssh-access to the laptop.
> >
> > As a least resort. root ssh - SHUDDER - Ooops now I spilled my preferred
> > password for that :)
> >
> > Thanks,
> >
> > 	tglx