All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Lapo TIN" <lapolapolapo@tin.it>
To: <linux-smp@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: smp and irq conflict
Date: Thu, 1 Feb 2007 18:46:00 +0100	[thread overview]
Message-ID: <45BE4003005C2845@vsmtp2.tin.it> (raw)

Dear all,
I have a problem with IRQs.

My pc has a CPU PentiumD945 (dual core) and a 2.6.19smp kernel.
I have two video acquisition board (four bt8t8 each) in the only two pci
slots of my motherboard. Thus I have a total of 8 bttv modules that are
working together, and the /proc/interrupts is as follows:
# cat /proc/interrupts
           CPU0       CPU1
  0:      13575          0   IO-APIC-edge      timer
  1:          2          0   IO-APIC-edge      i8042
  4:         11          0   IO-APIC-edge      serial
  8:          1          0   IO-APIC-edge      rtc
  9:          0          0   IO-APIC-fasteoi   acpi
 12:          4          0   IO-APIC-edge      i8042
 14:      22286          0   IO-APIC-edge      ide0
 17:       7073       2097   IO-APIC-fasteoi   uhci_hcd:usb5, eth0
 18:       2525          0   IO-APIC-fasteoi   bttv0, bttv7
 19:       2829          0   IO-APIC-fasteoi   bttv1, bttv4
 20:       2526          0   IO-APIC-fasteoi   bttv2, bttv5
 21:       2226          0   IO-APIC-fasteoi   bttv3, bttv6
 22:          2          0   IO-APIC-fasteoi   ehci_hcd:usb1, uhci_hcd:usb4
 23:         86          0   IO-APIC-fasteoi   uhci_hcd:usb2
 24:          0          0   IO-APIC-fasteoi   uhci_hcd:usb3
NMI:          0          0
LOC:      13484      13502
ERR:          0
MIS:          0
You can see that IRQ18 is shared between bttv0 and bttv7, IRQ19 between
bttv1 and bttv4 and so on.

Sometimes it crashes. It seems a matter of conflict in IRQ.
With only one video board everything is ok, but with two, they shared irq
and something goes wrong... 
How can I tell to the kernel to not to share the IRQ for these boards ?
I think (I don't know if I'm right) that this could be the problem.

I even tried with another motherboard, and doing cat /proc/interrupts the
situation was the same, except for 'eth0' that was together with bttv0 and
bttv7... so it was even worst ! it crashes after few minutes.

I tried to read IO-APIC.txt in Documentation/i386/ folder, but I didn't
understand how to avoid the coupling of IRQ.
Thanks
Lapo



             reply	other threads:[~2007-02-01 17:47 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-01 17:46 Lapo TIN [this message]
2007-02-02  4:32 ` smp and irq conflict Andrew Morton
2007-02-02  4:32   ` Andrew Morton
2007-02-02  5:22   ` Len Brown
2007-02-02 14:52 ` Bill Davidsen
2007-02-05 10:33   ` Benny Amorsen
2007-02-14 16:45     ` Bill Davidsen
     [not found] <fa.bd33YMixT9/jJwHfbD/DebGgVXs@ifi.uio.no>
2007-02-01 23:29 ` Robert Hancock
2007-02-02  0:04   ` Lapo TIN
2007-02-02  0:04   ` Lapo TIN
2007-02-02  0:04   ` Lapo TIN
2007-02-02  0:59     ` Robert Hancock
2007-02-02 11:08     ` Erik Mouw
2007-02-14 17:59       ` Manu Abraham
  -- strict thread matches above, loose matches on Subject: below --
2007-02-01 17:46 Lapo TIN
2007-02-01 17:46 Lapo TIN

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=45BE4003005C2845@vsmtp2.tin.it \
    --to=lapolapolapo@tin.it \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-smp@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.