I have the exact same problem and the exact same questions. I haven't seen any responses to Greg's email, so I thought I would reiterate the question. Anyone have any insight? Thanks, Joel > Hi, > > I've been working on getting my linux system set up for recording with > jack/ardour. I came across the "Low Latency mini howto": > http://www.djcj.org/LAU/guide/Low_latency-Mini-HOWTO.php3 > > At the end, it talks about setting up IRQs such that the sound card is > at a high priority relative to other devices in the system. However, > all the information in the doc pertains to non-APIC machines. What > about an APIC-enabled machine? > > The output of 'cat /proc/interrupts' shows my sound card (ICE1712) dead > last: > > CPU0 CPU1 > 0: 6628091 0 IO-APIC-edge timer > 1: 6 0 IO-APIC-edge keyboard > 2: 0 0 XT-PIC cascade > 9: 0 0 XT-PIC acpi > 12: 803 0 IO-APIC-edge PS/2 Mouse > 15: 5 0 IO-APIC-edge ide1 > 16: 0 0 IO-APIC-level usb-uhci, usb-uhci > 18: 4178 0 IO-APIC-level libata, usb-uhci > 19: 320 0 IO-APIC-level usb-uhci > 20: 6406 0 IO-APIC-level eth0 > 21: 0 0 IO-APIC-level ICE1712 > NMI: 0 0 > LOC: 6628191 6628246 > ERR: 0 > MIS: 0 > > output of: lspci -v -s 02:01.0 > 02:01.0 Multimedia audio controller: IC Ensemble Inc ICE1712 [Envy24] > (rev 02) > Subsystem: IC Ensemble Inc: Unknown device d634 > Flags: bus master, medium devsel, latency 32, IRQ 21 > I/O ports at 8000 [size=32] > I/O ports at 8400 [size=16] > I/O ports at 8800 [size=16] > I/O ports at 8c00 [size=64] > Capabilities: [80] Power Management version 1 > > I've tried manually setting IRQs in the BIOS, moving the card around, > etc. No amount of tweaking can move it any higher in the list. (It's > set to IRQ 10 in the BIOS) > > I guess my question is: Does the IRQ priority matter when IRQs are > abstracted by the APIC? If so, how does one change the priority in this > situation? I'm running 2.4.22, with the low latency and kernel > preemption patches installed. > > Thanks, > Greg > > -- > Greg Jednaszewski > greg@xxxxxxxxxxxxxx
