[PlanetCCRMA] pci latency_timer , usb soundcard

Florent Berthaut hitmuri at no-log.org
Mon Jan 21 12:02:01 2008

Hi everyone,

i have a problem with my new laptop and fedora 8 ccrma.
I have a lot of xruns when trying to use my m-audio fast track pro (usb) 
, so i decided to try to change the latency timer (which worked well 
with my previous laptop) for the usb controller.
But when i do :
/sbin/setpci -v -s 00:1d latency_timer=ff

and then : /sbin/lspci -v, the latency timer still shows 0 :

00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI 
Controller #1 (rev 03) (prog-if 20 [EHCI])
        Subsystem: Samsung Electronics Co Ltd Unknown device c510
        Flags: bus master, medium devsel, latency 0, IRQ 20

So how can i change it ?

I tryed dmesg and at some point it says:

ACPI: PCI Interrupt 0000:00:1d.0[A] -> GSI 23 (level, low) -> IRQ 20
PCI: Setting latency timer of device 0000:00:1d.0 to 64
uhci_hcd 0000:00:1d.0: UHCI Host Controller
uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus number 5
uhci_hcd 0000:00:1d.0: irq 20, io base 0x00001840

So the latency timer seems to be set to 64 .

Can i change the startup script which set this ?