25 Aug
2010
25 Aug
'10
10:34 a.m.
--- On Tue, 8/24/10, David Santamauro <david.santamauro(a)gmail.com> wrote:
From: David Santamauro
<david.santamauro(a)gmail.com>
Subject: Re: [LAU] irq sharing
To: "Mark Knecht" <markknecht(a)gmail.com>
Cc: "LAU" <linux-audio-user(a)lists.linuxaudio.org>
Date: Tuesday, August 24, 2010, 11:55 AM
On Tue, 24 Aug 2010 08:30:39 -0700
Mark Knecht <markknecht(a)gmail.com>
wrote:
this has nothing to do with
wow, how backward! (pun intended :)
Would a PCI ribbon extender like this one help ?
http://www.plinkusa.net/webR1PCI1-1R.htm
I know you can find PCI risers of various length. I used to use one in my mini ITX
multimedia server some long time ago. Don't remember the specs now but that should
allow you to twist things back to a normal position (hopefully).
J.
On Tue, Aug 24, 2010 at 8:13 AM, David
Santamauro
<david.santamauro(a)gmail.com>
wrote:
>
> Mark,
>
>
> On Tue, 24 Aug 2010 06:54:30 -0700
> Mark Knecht <markknecht(a)gmail.com>
wrote:
>
>> On Tue, Aug 24, 2010 at 5:10 AM, David
Santamauro
>> <david.santamauro(a)gmail.com>
wrote:
>> >
>> > Hi,
>> >
>> >
>> > Is there a way to forcibly assign
ICE1712 to another IRQ? I just
>> > want to test the theory.
>> >
>>
>> IRQ's and their numbering are physical
things. Their assignment is
>> made, fundamentally, when the
motherboard is
designed and is
>> hardwired based on the PC board traces.
You
cannot change those.
>>
>> For desktop machines the control you do have
is to move PCI
>> devices to different PCI slots. Asus
motherboards are usually
>> pretty good about calling out what slots
share interrupts with
>> other devices. Check your MB manual.
>>
>> If you don't have a manual use your eyes and
think about the whole
>> IRQ list. (Not just the part you
showed.)
Look for another PCI
>> card that seems to be on an interrupt by
itself and then switch
>> that card with your sound card.
>
> Manual says PCI at irq 20.
>
>>
>> For USB devices, if you have multiple USB
controllers and _if_ they
>> use different IRQs, then you may be able
to
choose a different
>> controller by choosing a different USB
connector to plug into. Move
>> your USB devices if this appears to be
true
about your motherboard.
>> (It is on many of mine...)
>>
>> Note that sharing IRQs with a USB controller
isn't necessarily
>> bad. It depends on what sort of USB
device is
attached, how its
>> driver is written, and how many
interrupts it
generates. However,
>> all things being equal, it's better
if
everything is completely
>> separated as that allows very little
interaction.
>
> thanks for the time. I only have one PCI slot,
but 3 empty PCI-x
> slots.
>
> I basically unplugged all USB devices as well as
shut off both
> network interfaces and on board audio
interface
in the bios and the
> noise persists ...
>
> Not sure what to try next, this was a
shot-in-the-dark.
David
David,
Well, at first blush that implies to me interrupts. Is the any card good? Have you tried
it in
another system?
the card works fine on the same hardware under 64-bit
windows7. I'm
trying to get it working 100% in fedora 12 64-bit with an
rt-kernel
(multi-os machine). I agree, interrupts are probably not
the issue.
Last time I was fiddling with this problem I had suspected
64-bit
linux drivers as it works in the 32-bit machine I have.
This was a long time ago in my chip
design architect history but I
helped write one of the early versions of the
PCI-x
spec for bridging
devices. IIRC PCI-x host controllers were
supposed to
correctly handle
both 32-bit and 64-bit PCI cards when plugged
into
those slots so
(according to the original spec written maybe 12
years
ago) if your
card physically plugs into whatever connectors
your MB
provides it
should work. (I.e. - PCI-x slows down to become
PCI.)
However if you
had any PCI-x cards they would slow down also.
Not a
problem in your
case it seems.
Obviously we don't want to damage
anything so I'd check your MB
manual on this, as well as looking at any BIOS
for any
settings or
clues about allowing PCI cards in PCI-x slots.
You'll
find a
supporting position here:
http://en.wikipedia.org/wiki/Pci-x
I read that as well, but my MB pci-x slots are (apparently)
backwards
(pardon my ignorance)
see page 7
http://www.tyan.com/manuals/m_s5396_120.pdf
... backwards, meaning, I'd have to stick the card in
backwards.
David
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