[LAU] kernel changes

[Ralf Mardorf]

On Sun, 2013-02-10 at 09:59 -0800, Len Ovens wrote:
> On Sun, February 10, 2013 9:34 am, Louis Gorenfeld wrote:
> 
> > Also, grab rtirq and run that if you haven't. I'd assume if you're
> > using a music-oriented distro that this is all already done.
> 
> Change the priority in the rtirq conig file before using it. It comes set
> up to prioritize internal/pci sound devices over either USB or FW. Choose
> a USB port and always use the same physical port (assuming you have picked
> one on it's own irq) and put that USB port first... by going USB3
> something something USB for example. This puts USB3 first and all the
> other USB ports at the end. (USB3 happens to be the good one on my
> machine, yours may be different)
> 
> This would be a great place for some automated setup BTW. A dialog that
> pops up if you plug a USB sound card in to a port that uses a shared IRQ
> suggesting to try another port even.

Sometimes it's possible to unbind devices, but I never experienced a
serious difference between a simple set up machine and a special tuned
machine:

$ cat tuning
#!/bin/bash

# sudo bash tuning - Ubuntu Studio Quantal
# 2012/Nov/04

### http://www.mythtv.org/wiki/PCI_Latency
###
http://wiki.linuxmusicians.com/doku.php?id=system_configuration#pci_bus_latency

### Bluetooth
service bluetooth stop

### Network
#service network-manager stop
#service networking stop # does cause serious issues
#modprobe -r r8169 # Ethernet NIC driver

### TerraTec EWX 24/96
modprobe -r snd_ice1712

### Others
modprobe -r firewire-ohci
modprobe -r firewire_core
service cups stop
modprobe -r ppdev # parallel port
modprobe -r lp    # printer

### Unbinding devices
echo -n "0000:00:13.2" > /sys/bus/pci/drivers/ohci_hcd/unbind
echo -n "0000:00:13.4" > /sys/bus/pci/drivers/ohci_hcd/unbind

### Log file
l="log/tuning.log"
#echo "$ lspci -v                       "  > $l
#lspci -v                                 >> $l
#echo                                     >> $l
echo "$ /etc/init.d/rtirq status       "  > $l
/etc/init.d/rtirq status                 >> $l
echo "$ grep 18: /proc/interrupts"       >> $l
grep 18: /proc/interrupts                >> $l
echo                                     >> $l
echo -n $(date)" - "$(uname -r)" - "     >> $l
cat /etc/issue                           >> $l
echo "##############################" ; cat $l

exit 0