[linux-audio-user] Tascam US-122, Laptop and Keyboard

Ryan Gallagher ruinaudio at comcast.net
Thu Mar 24 09:31:47 EST 2005

On Thu, 2005-03-24 at 14:03 -0500, Lee Revell wrote: 
> On Thu, 2005-03-24 at 13:49 -0500, Lee Revell wrote:
> > Is the USB irq shared with anything?
> Never mind, I see that it is shared, and with a pretty "heavy" device
> (the network card).

There's two similar (except for hardware) user experiences being
reported here... in my case I was able to eliminate "shared IRQ" issues.
By issuing the "acpi_irq_balance" kernel parameter.  Currently my irq
assignment is:

  0:     228818          XT-PIC  timer  0/28818
  1:        617          XT-PIC  i8042  0/617
  2:          0          XT-PIC  cascade  0/0
  7:         63          XT-PIC  Intel 82801DB-ICH4, eth0  0/63
  8:          2          XT-PIC  rtc  0/2
  9:      11329          XT-PIC  acpi, radeon at pci:0000:01:00.0  0/11329
 10:        727          XT-PIC  uhci_hcd:usb2, ehci_hcd:usb4  0/727
 11:          3          XT-PIC  uhci_hcd:usb1, uhci_hcd:usb3, ohci1394
 12:      13706          XT-PIC  i8042  1/13706
 14:       1701          XT-PIC  ide0  0/1701
 15:       5553          XT-PIC  ide1  0/5553

It doesn't seem to matter what USB bus it's on (or for that matter if
irq's are "reshuffled" or not) so I'm suspicious of some intrinsic
kernel or driver issue (barring some weird hardware hangup).  I've got
the week off so I'll do some further testing (I also have the builtin
ac97 chip and another USB device (emi 2|6).

> Is this the case for everyone who is having the problem?
> Does disconnecting the network cable help?

As reported above, eth0 is on another IRQ.  Also all my kernels are
patched with Ingo Molnar's RP patches ( through 2.6.12.rcX).  I'm
unthreading whatever IRQ the device is on (10 or 11 and sometimes both).

Ryan Gallagher <ruinaudio at comcast.net>

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