Re: un/shared IRQ problem (was: Re: 2.6.18 - another DWARF2)

[Andrew Morton <akpm@osdl.org>]

On Thu, 19 Oct 2006 08:39:21 +0200
Martin Lorenz <martin@lorenz.eu.org> wrote:

> On Wed, Oct 18, 2006 at 11:26:03PM -0700, Andrew Morton wrote:
> > On Wed, 18 Oct 2006 08:34:31 +0200
> > Martin Lorenz <martin@lorenz.eu.org> wrote:
> > 
> > > On Tue, Oct 17, 2006 at 11:52:16AM -0700, Jesse Brandeburg wrote:
> > > > On 10/16/06, Martin Lorenz <martin@lorenz.eu.org> wrote:
> > > > >just got the following on resume:
> > > > >
> > > > >[87026.706000]  [<c0251745>] e1000_open+0xcd/0x1a4
> > > > >[87026.714000] DWARF2 unwinder stuck at syscall_call+0x7/0xb
> > > > >[87026.715000] Leftover inexact backtrace:
> > > > >[87026.715000] e1000: eth0: e1000_request_irq: Unable to allocate interrupt
> > > > >Error: -16
> > > > 
> > > > I'm pretty sure this isn't an e1000 problem.  you need to talk to
> > > > whoever is maintaining the IRQ subsystem for x86.  E1000 is attempting
> > > > to register a shared interrupt and someone has already registered that
> > > > interrupt unshared.
> > > 
> > > interestingly though it always involves e1000 when I see dumps like this.
> > > I already reported more of those :-)
> > > this one dosen't seem to do any harm to system stability. it occurs on every
> > > suspend/resume and I can circumvent it by disabling msi
> > > 
> > > > 
> > > > looks like several devices are sharing IRQ 201 (aka GSI 16) and ahci
> > > > or usb uhci_hcd is likely the problem, or the (acpi) power management
> > > > subsystem.
> > > > 
> > > > Hope this helps get the right people involved.
> > > 
> > > thank you
> > 
> > Could we see the /proc/interrupts please, so we can find out where the
> > clash is happening?
> 
> 
> here you are
> 
> ~# cat /proc/interrupts
>            CPU0       CPU1
>   0:   76521957    2009390    IO-APIC-edge  timer
>   1:      39599          0    IO-APIC-edge  i8042
>   8:        128          0    IO-APIC-edge  rtc
>   9:     415044          0   IO-APIC-level  acpi
>  12:     862451          0    IO-APIC-edge  i8042
>  58:      68014     326850         PCI-MSI  libata
>  66:     508910      17187   IO-APIC-level  sdhci:slot0, uhci_hcd:usb3
>  74:    3156375          0   IO-APIC-level  uhci_hcd:usb2, ohci1394, HDA Intel
>  82:     134828          0   IO-APIC-level  uhci_hcd:usb4, ehci_hcd:usb5
>  90:      46548          0         PCI-MSI  eth0
> 201:     100133          0   IO-APIC-level  uhci_hcd:usb1, yenta, i915@pci:0000:00:02.0
> NMI:          0          0
> LOC:   78530935   78520308
> ERR:          0
> MIS:          0
> 

There are already three interrupt sources on 201, so they are all happy to
share.

It's e1000.  Jesse, you fibbed ;)

static int e1000_request_irq(struct e1000_adapter *adapter)
{
	...
	if (adapter->have_msi)
		flags &= ~IRQF_SHARED;