6 Feb
2007
6 Feb
'07
8:51 p.m.
Pieter Palmers wrote:
mea wrote:
Hello,
I managed to patch and install the 2.6.20-rc6 kernel with
patch-2.6.20-rc6-rt6 following more or less the instructions from the
links on http://freebob.sourceforge.net, system configuration. It boots
almost without any errors. (This is a little off-topic, but I would
appreciate any tips> The only thing I didn't manage to fix after many
reconfigurations is that I don't see any boot messages and also the
terminals (Ctrl-alt-F*) vanished.)
I start qjackctl with
set_rlimits qjackctl and then set_rlimits ardour
Connecting to jack server causes many xruns and ardour soon gets
disconnected. No difference if I run only jackd with command line options.
What now?
Like you can see in my prevoius post, almost every device uses IRQ11,
Should I fix this in the BIOS? In BIOS there is a list like this>
INTA PCI IRQ [11] where I can change the number
INTB PCI IRQ [11]
...etc until INTH.
No idea what letter is what.
I also downloaded rtirq, but really, the information I could get about
it is far too cryptical for my level of knowledge. Is it so, that
/etc/rtirq.conf gives higher priorities to some chosen threads? Then I
could give a higher priority to f.e. ohci1394?
Thank you in advance for your time,
Best
Martin
Pieter Palmers wrote:
It's really ashame that almost every
device on your system uses IRQ11.
That cannot be good for performance, especially the radeon might cause
problems.
mea wrote:
Thank you for the quick and informative answer. I start qjackctl
first, with server "set_rlimits jackd -R". I also tried just
"set_rlimits jackd -R -d freebob etc. from a terminal, no difference.
/etc/set_rlimits.conf looks like this:
@audio /usr/local/bin/jackd nice=-1 rtprio=85 memlock=59000
@audio /usr/local/bin/qjackctl nice=-1 rtprio=84 memlock=59000
@audio /usr/bin/ardour nice=-1 rtprio=83 memlock=25000
lspci -v :
2:07.0 FireWire (IEEE 1394): Texas Instruments TSB43AB21
IEEE-1394a-2000 Controller (PHY/Link) (prog-if 10 [OHCI])
Lucky there!
cat /proc/interrupts
CPU0
0: 11707467 XT-PIC timer
1: 48 XT-PIC i8042
2: 0 XT-PIC cascade
8: 1 XT-PIC rtc
9: 32729 XT-PIC acpi
11: 16353479 XT-PIC yenta, eth0, ohci1394, Intel
82801DB-ICH4, ehci_hcd:usb1, uhci_hcd:usb2, uhci_hcd:usb3,
uhci_hcd:usb4, radeon@pci:0000:01:00.0 Hello from Prague,
I bought the firewire soundcard Edirol FA-66. Yesterday morning I
compiled freebob, recompiled jack and within half an hour I already
saw all 6 inputs and outputs in qjackctl. What? Recording on linux
is hard? Pha! I thought but unfortunately my moment of victory
didn't last long. On all recordings there is a strange cracking
sound, not all the time, but every couple of seconds. No xruns
though. Before I bought this device I used to record through the
internal soundcard of my thinkpad R40, running all programs as root
and this 'sort of' worked. So I thought I should first of all make
sure all my apps can run as user. After a lot of reading (I spent
all day on this yesterday before I decided to consult this list) I
figured the best approach for me would be to use set_rlimits,
because slackware doesn't have PAM, and I never patched a kernel
before. As I understand these are the 3 possibilities for programs
to run in realtime right? Well, in short I can now run qjackctl,
jack and ardour as user without xruns, but this weird cracking is
still on the recordings. To make sure it was not an ardour issue I
tried sooperlooper, and the noise is still there. I suspect the
trouble is probably freebob, because I didn't have this issue before
and maybe I should have written on their list, but I am not
completely sure and I found very useful information here before, so
here I am, asking for any advice, because I don't know what to do
anymore. Here is some more information about my setup>
The crackles you hear are due to libfreebob not being able to process
the firewire packets fast enough. This means lost packets and hence
lost audio data. You would expect xruns when this happens, but
freebob-1.0 doesn't report dropped packets as xruns, this could be
called a bug. We'll fix this in the next version.
In order to use FreeBoB, it is really recommended to use a realtime
patched kernel. We are doing in userspace what is normally done in
kernel space, and hence we need to meet very strict deadlines to be
able to. When using a realtime patched kernel that is configured
correctly (see
http://freebob.sourceforge.net/index.php/System_Configuration_Hints),
no packets are dropped and this problem does not occur.
Having said this, you can probably improve things on a standard
kernel if you allow user processes to request SCHED_FIFO scheduling
(realtime scheduling). As a test you can run jackd+freebob as root
and see if the problem persists. Remember to start jackd in realtime
mode:
e.g.
jackd -R -p60 -d freebob -p512
Thinkpad R40, Pentium4, 512MbRAM
You should check the brand of the firewire
controller that you are
using. (some) Thinkpads have a Ricoh firewire controller built in,
and that is a very buggy piece of hardware. It will never work
properly with freebob because it fails on isochronous traffic. (check
this using lspci -v)
The solution for that is to use a cardbus firewire controller.
Chipsets from Via, Texas Instruments and Nec are working fine for me.
Slackware 10.2
uname -r 2.6.13
Should it be possible, maybe consider switching to a more audio
friendly distro...
Greets,
Pieter Palmers
FreeBoB developer
12: 33 XT-PIC i8042
14: 82318 XT-PIC ide0
15: 271529 XT-PIC ide1
ups!
I will have to patch the kernel to be able to use rcirq right?
AFAIK yes. I would
really recommend using a -rt patched kernel.
Pieter