[LAU] Issues with JACK

[Len Ovens]

On Wed, March 6, 2013 11:46 am, Gabbe Nord wrote:
> Hello all, and thank you so much for your answers! I feel like I need to
clear up a few things here for my own sake, sorry for being slow: * You
are referring to an "I/O" USB card that connects to PCI-E as a solution,
right?

Yes. See my comments below as the two are related :)

> * I don't really know what IRQs are to which port etc, but I have my
soundcard plugged in to one port, and my USB-hub with everything else on
on
> yet another. I also have USB-ports on the front of my case, which are
connected to the motherboard directly. Can I somehow find out what's
connected to what inside the computer, and how do I modify my IRQ-files
to
> correspond to where I have my soundcard? Will unplugging/replugging and
using lsusb -t do that for me?

You posted your cat /proc/interrupts a few days ago. In there I could only
see two USB ports at all. USB1 and USB2. Not only that, but both USB ports
use the same IRQ. What this means is that, even though there are some more
physical USB ports on your machine, they are only there because the MB has
an internal USB hub (or two). The only way to get beyond that I can see is
to add a new USB interface on a fresh IRQ. I don't know what kind of slots
your MB has (PCI or PCIe or both) but USB cards should be available for
either... probably cheaper than a new audio card. Make sure it is USB2.0
or USB3.0 (+2 +1.1) and not just 1.1 ...

I normally just use dmesg to find out what the new device is:
[363472.113041] usb 1-7: new high-speed USB device number 3 using ehci-pci
That says the usb stick I inserted is in USB1 (a USB2.0 port) and that is
device 3 (out of 4 I am guessing)

lsusb -t gives this before I add the device:
$ lsusb -t
/:  Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/8p, 480M
    |__ Port 8: Dev 2, If 0, Class=stor., Driver=usb-storage, 480M
(Dev 2 is my system disk right now)
 and this after:
$ lsusb -t
/:  Bus 05.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/8p, 480M
    |__ Port 7: Dev 5, If 0, Class=stor., Driver=usb-storage, 480M
    |__ Port 8: Dev 2, If 0, Class=stor., Driver=usb-storage, 480M

Hmm, now it is device 5, so I guess it is not out of 4. I don't know what
the port is though. My cat /proc/interrupts looks like this:

 16:    1881681   IO-APIC-fasteoi   uhci_hcd:usb2, uhci_hcd:usb5, nouveau
 17:    1985740   IO-APIC-fasteoi   eth0
 18:      66775   IO-APIC-fasteoi   ata_piix, uhci_hcd:usb4
 19:          0   IO-APIC-fasteoi   uhci_hcd:usb3
 20:     210124   IO-APIC-fasteoi   snd_ens1370
 22:   25879534   IO-APIC-fasteoi   snd_ice1712
 23:    1281786   IO-APIC-fasteoi   ehci_hcd:usb1

The interesting thing to note is that when I told the BIOS _NOT_ to give
my USB devices IRQs The kernel does so instead and USB1 (as you can see)
now has it's own IRQ, it used to share 16... Not so good as it is the only
high speed USB device I have.



> On a different note: If I were to get a new soundcard instead, does
anyone
> have recommendations of non-USB cards? There seems to be some issues
with
> PCI-cards and newer motherboards (I have a z77 intel chipset or
something)
> that uses emulated and not native PCI. I guess this resricts me from
using
> PCI-cards? (referring to
> http://www.linuxmusicians.com/viewtopic.php?f=6&t=10106 ).
> I'm using 48khz and 24bit right now, and I record mostly acoustic guitar
and vocals (both singing and rap vocals). Is there any reason for me to
run
> 24bit, maybe I could get away with 16bit? I do not really want to reduce
quality, even by a little, so if there's any reason not to go 16bit I
probably won't.

If you already have a 24bit device, get it working. There are not very
many PCIe sound cards around and those that are seem to be (overly)
pricey. Even a PCI 24 bit card will probably cost you more than a new USB
card. I think 24bit is worth having, I just figured you were running
USB1.1 at 16 bits right now. I was mistaken.



-- 
Len Ovens
www.OvenWerks.net