[LAD] rtirq - previously Re: MidiSport vs. UA25

[Ralf Mardorf]

Arnout Engelen wrote:
> I haven't looked into rtirq yet (I really should), but if I understand 
> correctly rtirq does automatically what I did manually: find out which IRQ 
> the device you're interested in is connected to, and give that IRQ a 
> higher rtprio.
>
> To see the current rtprio's of your IRQ's, do:
>
>   ps axHo user,lwp,pid,rtprio,ni,command | grep irq
>
> To increase the rtprio of some irq manually:
>
>   chrt -f -p <prio> <pid>

This is from my rtirq: "RTIRQ_NAME_LIST="rtc snd usb3 i8042"" RTC seems 
to be IRQ-8, the sound card is IRQ-21 and the USB MIDI device is IRQ-17.

Why are there IRQ-1 and IRQ-12 having higher rtprio than USB?

Is "usb3" for rtirq correct for "SysFS ID: /devices/[snip]/usb2/[snip]? 
There seems to be no usb0, that's why I guess it's wrong, but I guess 
Rui once has written "usb3".

Is there a reason not to give usb3 a higher rtprio than snd, at least 
when I only need a sequencer?

How can I see which devices do use what IRQ? Perhaps IRQ-17 is used by 
other devices too.

$ ps axHo user,lwp,pid,rtprio,ni,command | grep IRQ
root       104   104     50   - [IRQ-9]
root       402   402     74   - [IRQ-12]
root       403   403     75   - [IRQ-1]
root       411   411     90   - [IRQ-8]
root       971   971     50   - [IRQ-16]
root       992   992     50   - [IRQ-17] *USB MIDI device*
root      1021  1021     80   - [IRQ-19]
root      1028  1028     50   - [IRQ-22]
root      1383  1383     50   - [IRQ-18]
root      1521  1521     50   - [IRQ-14]
root      2082  2082     50   - [IRQ-7]
root      2101  2101     50   - [IRQ-25]
root      2369  2369     85   - [IRQ-21] *Sound card*
root      4302  4302     50   - [IRQ-4]
1000     14174 14174      -   0 grep IRQ

------------------------------------------------------------------------

*Only Swissonic MIDI USB device is connected*

$ hwinfo --usb
01: USB 00.0: 10a00 Hub                                        
  [snip]

02: USB 00.0: 10a00 Hub
  [snip]

03: USB 00.0: 10a00 Hub
  [snip]

04: USB 00.0: 0000 Unclassified device
  [Created at usb.122]
  UDI: /org/freedesktop/Hal/devices/usb_device_170b_11_noserial_if0
  Unique ID: FKGF.HOkU9LTmHW8
  Parent ID: pBe4.PaupGMfzSp8
  SysFS ID: /devices/pci0000:00/0000:00:13.1/usb2/2-1/2-1:1.0
  SysFS BusID: 2-1:1.0
  Hardware Class: unknown
  Model: "Unclassified device"
  Hotplug: USB
  Vendor: usb 0x170b
  Device: usb 0x0011
  Revision: "0.01"
  Driver: "snd-usb-audio"
  Driver Modules: "snd_usb_audio"
  Speed: 12 Mbps
  Module Alias: "usb:v170Bp0011d0001dc00dsc00dp00ic01isc03ip00"
  Driver Info #0:
    Driver Status: snd_usb_audio is active
    Driver Activation Cmd: "modprobe snd_usb_audio"
  Config Status: cfg=new, avail=yes, need=no, active=unknown
  Attached to: #6 (Hub)

05: USB 00.0: 10a00 Hub
  [snip]

06: USB 00.0: 10a00 Hub
  [snip]

07: USB 00.0: 10a00 Hub
  [snip]

hwinfo --usb-ctrl
[snip]                     
24: PCI 13.1: 0c03 USB Controller (OHCI)
  [Created at pci.296]
  UDI: /org/freedesktop/Hal/devices/pci_1002_4388
  Unique ID: 9n5e.Z94ELKUtK5C
  SysFS ID: /devices/pci0000:00/0000:00:13.1
  SysFS BusID: 0000:00:13.1
  Hardware Class: usb controller
  Model: "ASUSTeK USB Controller"
  Vendor: pci 0x1002 "ATI Technologies Inc"
  Device: pci 0x4388
  SubVendor: pci 0x1043 "ASUSTeK Computer Inc."
  SubDevice: pci 0x81ef
  Driver: "ohci_hcd"
  Driver Modules: "ohci_hcd"
  Memory Range: 0xfe02d000-0xfe02dfff (rw,non-prefetchable)
  IRQ: 17 (29 events)
  Module Alias: "pci:v00001002d00004388sv00001043sd000081EFbc0Csc03i10"
  Driver Info #0:
    Driver Status: ohci-hcd is active
    Driver Activation Cmd: "modprobe ohci-hcd"
  Config Status: cfg=new, avail=yes, need=no, active=unknown
[snip]

------------------------------------------------------------------------

$ hwinfo --sound
09: PCI 306.0: 0401 Multimedia audio controller                
  [Created at pci.296]
  UDI: /org/freedesktop/Hal/devices/pci_1412_1712
  Unique ID: Kaa7.J4wu6rKmng4
  Parent ID: qscc.ULOo3yhA66C
  SysFS ID: /devices/pci0000:00/0000:00:14.4/0000:03:06.0
  SysFS BusID: 0000:03:06.0
  Hardware Class: sound
  Model: "TERRATEC EWX 24/96"
  Vendor: pci 0x1412 "VIA Technologies Inc."
  Device: pci 0x1712 "ICE1712 [Envy24] PCI Multi-Channel I/O Controller"
  SubVendor: pci 0x153b "TERRATEC Electronic GmbH"
  SubDevice: pci 0x1130 "EWX 24/96"
  Revision: 0x02
  Driver: "ICE1712"
  Driver Modules: "snd_ice1712"
  I/O Ports: 0xcf00-0xcf1f (rw)
  I/O Ports: 0xce00-0xce0f (rw)
  I/O Ports: 0xcd00-0xcd0f (rw)
  I/O Ports: 0xcc00-0xcc3f (rw)
  IRQ: 21 (26376 events)
  Module Alias: "pci:v00001412d00001712sv0000153Bsd00001130bc04sc01i00"
  Driver Info #0:
    Driver Status: snd_ice1712 is active
    Driver Activation Cmd: "modprobe snd_ice1712"
  Config Status: cfg=new, avail=yes, need=no, active=unknown
  Attached to: #16 (PCI bridge)