Thinkpads Forum

Posted: **Thu Sep 19, 2013 6:03 am**

Is there away to manually assign IRQ numbers to certain devices? This is on a T410. What i want is to have my firewire port assigned to its own IRQ number.

Code: Select all

possum@debian:~$ cat /proc/interrupts
           CPU0       CPU1       CPU2       CPU3       
  0:        126          3          3          4   IO-APIC-edge      timer
  1:        370        377        371        382   IO-APIC-edge      i8042
  8:          1          0          0          0   IO-APIC-edge      rtc0
  9:        743        749        745        738   IO-APIC-fasteoi   acpi
 12:      84784      84969      84682      84961   IO-APIC-edge      i8042
 16:          0          0          0          0   IO-APIC-fasteoi   mmc0
 19:         21         17         20         27   IO-APIC-fasteoi   firewire_ohci, firewire_ohci, ehci_hcd:usb2, ips
 23:         19         18         17         13   IO-APIC-fasteoi   ehci_hcd:usb1
 40:        434        407        356        407   PCI-MSI-edge      eth0
 41:       7120       7095       7158       7133   PCI-MSI-edge      ahci
 42:      81382      81481      81533      81367   PCI-MSI-edge      i915
 43:      26299      26652      27492      27802   PCI-MSI-edge      iwlwifi
 44:         52         54         53         50   PCI-MSI-edge      snd_hda_intel
NMI:          0          0          0          0   Non-maskable interrupts
LOC:     331702     160937     320881     188555   Local timer interrupts
SPU:          0          0          0          0   Spurious interrupts
PMI:          0          0          0          0   Performance monitoring interrupts
IWI:          0          0          0          0   IRQ work interrupts
RES:      11683      12197       9817      10702   Rescheduling interrupts
CAL:        479        676        468        654   Function call interrupts
TLB:       7463       1947       4702       1995   TLB shootdowns
TRM:          0          0          0          0   Thermal event interrupts
THR:          0          0          0          0   Threshold APIC interrupts
MCE:          0          0          0          0   Machine check exceptions
MCP:        806        806        806        806   Machine check polls
ERR:          0
MIS:          0

If you see IRQ19 its sharing a firewire port, usb port and intel ips. I thought a way to get around it was to add in an expresscard firewire but it chucked it on IRQ19 aswell.

Posted: **Fri Sep 20, 2013 5:07 am**

With an ACPI OS - not really.

Are you trying to work around an existing problem that stems from shared IRQs? Normally it causes no issues.

If you do have issues from the IRQ sharing, try to find a driver / Linux kernel patch that enables MSI (Message Signaled Interrupts) for your Firewire controller. According to what I know, the device supports MSI, at least in theory, but the drivers do not enable it by default. But of course maybe there is a reason why they don't. Maybe it's supported in theory, but doesn't work.

Thinkpads Forum

IRQ handling on T410

IRQ handling on T410

Re: IRQ handling on T410