Hi,
I recently upgrade my studio to a 3.8 lowlat kernel, I used to have kernel 2.6.32, and I began to have noise issues with my HDSP Multiface II. It’s a little noise that wasn’t there before, looks like an interference from the video card, and I can also hear another little noise whenever I move the mouse. Since hardware-wise I didn’t touch anything, I guess it’s a kernel related issue, such as an irq conflict maybe. /etc/init.d/rtirq status look like this:
PID CLS RTPRIO NI PRI %CPU STAT COMMAND
330 FF 90 - 130 0.0 S irq/19-firewire
723 FF 84 - 124 0.3 S irq/16-snd_hdsp
1014 FF 83 - 123 0.1 S irq/16-0000:0a:
87 FF 80 - 120 0.0 S irq/16-ehci_hcd
88 FF 79 - 119 0.1 S irq/23-ehci_hcd
99 FF 75 - 115 0.0 S irq/1-i8042
98 FF 74 - 114 0.0 S irq/12-i8042
46 FF 50 - 90 0.0 S irq/9-acpi
74 FF 50 - 90 0.0 S irq/18-ahci
77 FF 50 - 90 0.0 S irq/21-ata_piix
82 FF 50 - 90 0.0 S irq/21-ata_piix
89 FF 50 - 90 0.0 S irq/45-xhci_hcd
90 FF 50 - 90 0.0 S irq/46-xhci_hcd
91 FF 50 - 90 0.0 S irq/47-xhci_hcd
92 FF 50 - 90 0.0 S irq/48-xhci_hcd
93 FF 50 - 90 0.0 S irq/49-xhci_hcd
94 FF 50 - 90 0.0 S irq/50-xhci_hcd
95 FF 50 - 90 0.0 S irq/51-xhci_hcd
96 FF 50 - 90 0.0 S irq/52-xhci_hcd
100 FF 50 - 90 0.0 S irq/8-rtc0
267 FF 50 - 90 0.0 S irq/17-pata_mar
271 FF 50 - 90 0.0 S irq/19-pata_jmi
1010 FF 50 - 90 0.0 S irq/53-eth0
1519 FF 50 - 90 0.2 S irq/54-fglrx[0]
3 TS - 0 19 0.1 S ksoftirqd/0
10 TS - 0 19 0.1 S ksoftirqd/1
15 TS - 0 19 0.1 S ksoftirqd/2
19 TS - 0 19 0.1 S ksoftirqd/3
23 TS - 0 19 0.0 S ksoftirqd/4
27 TS - 0 19 0.0 S ksoftirqd/5
31 TS - 0 19 0.0 S ksoftirqd/6
35 TS - 0 19 0.0 S ksoftirqd/7
It seems the hdsp module is on the same irq as 2 other modules…