[LAU] Jack problems on Dell M90

[garryo]

Nathanael Anderson wrote:
> I'm hoping I'll be able to find someone else with a similar setup that 
> has overcome their problems to get realtime operation, at least in one 
> direction, with no xruns.

 > (edit)

 >  cat /proc/interrupts
 >            CPU0       CPU1
 >   0:   20489426          0    XT-PIC-XT        timer
 >   1:      14552          0    XT-PIC-XT        i8042
 >   2:          0          0    XT-PIC-XT        cascade
 >   5:          0          0    XT-PIC-XT        uhci_hcd:usb4
 >   7:       2008          0    XT-PIC-XT        ipw3945
 >   8:          2          0    XT-PIC-XT        rtc
 >   9:    2930465          0    XT-PIC-XT        acpi, uhci_hcd:usb3, 
nvidia
 >  10:        269          0    XT-PIC-XT        uhci_hcd:usb1, 
ehci_hcd:usb5
 >  11:    1627576          0    XT-PIC-XT        uhci_hcd:usb2, HDA Intel
 >  12:      16281          0    XT-PIC-XT        i8042
 >  14:      60131          0    XT-PIC-XT        libata
 >  15:      64207          0    XT-PIC-XT        libata
 > 218:    1624641          0   PCI-MSI-edge      eth0
 > NMI:          0          0   Non-maskable interrupts
 > LOC:    5672972   14563710   Local timer interrupts
 > RES:    9766464   13228888   Rescheduling interrupts
 > CAL:      46404      41727   function call interrupts
 > TLB:      21123      35433   TLB shootdowns
 > TRM:          0          0   Thermal event interrupts
 > SPU:          0          0   Spurious interrupts
 > ERR:          0
 > MIS:          0

the most obvious problem here is that your intel hda is sharing its 
interrupt with usb2.
try booting with noapic appended to the kernel line in your bootloader 
menu and see if that makes a difference. (it did on my box)


> Setup:
> Dell M90 (intel-hda audio)
> Kernel 2.6.24 RT PREMPT SMP from gentoo pro-audio feed
> quadro 1500fx with nvidia driver (i'd really like to keep this driver, 
> unless compiz works now with the nv driver)
> 

i have the notion that the nvidia binary driver doesnt work too well 
with RT. others here may be able to confirm that or otherwise

checkout: http://tapas.affenbande.org/wordpress/ for excellent info on 
RT setup and also:
http://irc.esben-stien.name/mediawiki/index.php/Setting_Up_Real_Time_Operation_on_GNU/Linux_Systems

hope the above was of some use, report back,
cheers G.