[LAU] Cracking sound via USB (ALSA urb.c:480: frame 5 active: -18)

[Robin Gareus]

On 05/25/2011 07:48 PM, Emanuel Rumpf wrote:
> 2011/5/25 Robin Gareus <robin at gareus.org>:
>>
>> You need to add 'threadirqs' to the kernel-boot option to enable
>> threaded IRQ handlers with 2.6.39.
>>
> Things have changed, I'm not quite sure how to do that these days.
> Add it to  GRUB_CMDLINE_LINUX_DEFAULT  in /etc/default/grub ? ? ?

Yes, but it depends on your bootloader and distro.
I use GRUB_CMDLINE_LINUX="i915.modeset=1 threadirqs"
in /etc/default/grub. run `sudo update-grub` after saving changes to
that file.

If you install the kernel as debian package the 'update-grub' part is
taken care of by dpkg's postinst script.

>> I'm waiting for feedback from Daniel about a 2.6.39 kernel for
>> openDAW/64studio. Stay tuned.
>>
>> The .config I'm currently using successfully on i386 thinkpad X60s is:
>>  http://rg42.org/_media/wiki/kernel/config-2.6.39.gz
>>
> Thanks.
> 
> There's a tool called irqbalance
> Running that, is it still recommended with threadirqs ?

I don't know. I do run irqbalance here; but it does not seem to have
effect on hardware-irqs [anymore] (see dumps below).

But I'm getting off-topic.
There are no crackles nor xruns here with and without irqbalance.
jackd2-svn-r4393, The UA-25 is on IRQ 18;


Are your crackles gone with the 'threadirqs' option?
robin



# cat /proc/interrupts
           CPU0       CPU1
  0:  278696424          6   IO-APIC-edge      timer
  1:     765597          0   IO-APIC-edge      i8042
  8:          1          0   IO-APIC-edge      rtc0
  9:   19624127          0   IO-APIC-fasteoi   acpi
 12:    9265100          0   IO-APIC-edge      i8042
 14:    2635256          4   IO-APIC-edge      ata_piix
 15:          0          0   IO-APIC-edge      ata_piix
 16:    1238945          0   IO-APIC-fasteoi   yenta, uhci_hcd:usb2,
i915 at pci:0000:00:02.0
 17:       6413          0   IO-APIC-fasteoi   uhci_hcd:usb3, firewire_ohci
 18:    2273102          2   IO-APIC-fasteoi   uhci_hcd:usb4, mmc0
 19:    7270696         23   IO-APIC-fasteoi   ehci_hcd:usb1, uhci_hcd:usb5
 40:          0          0   PCI-MSI-edge      PCIe PME
 41:          0          0   PCI-MSI-edge      PCIe PME
 42:          0          0   PCI-MSI-edge      PCIe PME
 43:          0          0   PCI-MSI-edge      PCIe PME
 44:    8880802         38   PCI-MSI-edge      hda_intel
 45:   20916424         16   PCI-MSI-edge      iwl3945
NMI:       2647       2909   Non-maskable interrupts
LOC:   77842296  233977838   Local timer interrupts
SPU:          0          0   Spurious interrupts
PMI:       2647       2909   Performance monitoring interrupts
IWI:          0          0   IRQ work interrupts
RES:   85016190  124517149   Rescheduling interrupts
CAL:     332967     582697   Function call interrupts
TLB:     849663     604581   TLB shootdowns
TRM:         12         12   Thermal event interrupts
THR:          0          0   Threshold APIC interrupts
MCE:          0          0   Machine check exceptions
MCP:       1144       1124   Machine check polls
ERR:          0
MIS:          0


# cat /proc/softirqs
                    CPU0       CPU1
          HI:         71          0
       TIMER:   78744168   77532112
      NET_TX:      93266     813476
      NET_RX:     104790      97888
       BLOCK:    1482548    3411882
BLOCK_IOPOLL:         71          0
     TASKLET:   10734408   19778443
       SCHED:    4012801    4799134
     HRTIMER:     215170     248879
         RCU:   21928395   24010120

# /etc/init.d/rtirq status
  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
  970 FF      88   - 128  0.0 S    irq/18-uhci_hcd	
  317 FF      84   - 124  0.2 S    irq/44-hda_inte	
  610 FF      80   - 120  0.0 S    irq/1-i8042	
  609 FF      79   - 119  0.0 S    irq/12-i8042	
  159 FF      50   -  90  0.1 S    irq/9-acpi	
  318 FF      50   -  90  0.0 S    irq/18-mmc0	
  321 FF      50   -  90  0.0 S    irq/16-i915 at pci	
  322 FF      50   -  90  0.0 S    irq/17-firewire	
  443 FF      50   -  90  0.0 S    irq/40-PCIe PME	
  444 FF      50   -  90  0.0 S    irq/41-PCIe PME	
  445 FF      50   -  90  0.0 S    irq/42-PCIe PME	
  446 FF      50   -  90  0.0 S    irq/43-PCIe PME	
  569 FF      50   -  90  0.0 S    irq/14-ata_piix	
  570 FF      50   -  90  0.0 S    irq/15-ata_piix	
  589 FF      50   -  90  0.0 S    irq/16-yenta	
  929 FF      50   -  90  0.0 S    irq/8-rtc0	
  963 FF      50   -  90  0.0 S    irq/19-ehci_hcd	
  967 FF      50   -  90  0.0 S    irq/16-uhci_hcd	
  969 FF      50   -  90  0.0 S    irq/17-uhci_hcd	
  972 FF      50   -  90  0.0 S    irq/19-uhci_hcd	
29970 FF      50   -  90  0.5 S    irq/45-iwl3945	
    3 TS       -   0  19  0.1 S    ksoftirqd/0	
  315 TS       -   0  19  0.2 S    ksoftirqd/1	
 3620 TS       - -20  39  0.0 S<   kvm-irqfd-clean	
24746 TS       -   0  19  0.0 S+   rtirq