9fans - fans of the OS Plan 9 from Bell Labs
 help / color / mirror / Atom feed
From: Charles Forsyth <forsyth@terzarima.net>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] ATA next
Date: Fri, 23 Jan 2004 09:11:31 +0000	[thread overview]
Message-ID: <ed8f1e8a629e33c8977cad10aa9684f0@terzarima.net> (raw)
In-Reply-To: <20040123071911.G28365@cackle.proxima.alt.za>

>>It all puts the lie to the above.  I must conclude that something
>>in the interrupt handling rather than in the ATA DMA code has
>>changed to cause so many more int 7s to occur.  I'm looking forward

i thought IRQ7 was generated when a device requested an interrupt
then incorrectly removed that irq signal before the cpu acknowledged it.
a quick google search seems to confirm that.
see http://www.geocrawler.com/archives/3/171/2000/5/0/3704984/
(ie, it's not the driver code as such that causes it, but the hardware.)

i wonder, though, whether it can happen if an interrupt
is configured as level-triggered in the controller or system
but is actually edge-triggered.  i didn't think there were level-triggered interrupts
on a system without PCI, but perhaps there are.
you might check your system's BIOS settings


  reply	other threads:[~2004-01-23  9:11 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-01-22 14:23 Lucio De Re
2004-01-22 15:22 ` jmk
2004-01-22 18:19   ` Lucio De Re
2004-01-22 19:13     ` jmk
2004-01-23  5:19       ` Lucio De Re
2004-01-23  9:11         ` Charles Forsyth [this message]
2004-01-23  9:37           ` Lucio De Re
2004-01-23 16:38           ` jmk
2004-01-23 16:47             ` C H Forsyth
2004-01-22 15:53 ` David Presotto
2004-01-22 18:36   ` Lucio De Re
2004-01-22 19:53     ` David Presotto
2004-01-23  5:55       ` [9fans] imap4d operation (Was: ATA next) Lucio De Re
2004-01-23 16:39         ` David Presotto
2004-01-22 20:10     ` [9fans] ATA next David Presotto
2004-01-23  7:11       ` Lucio De Re
2004-01-23  9:00         ` Lucio De Re
2004-01-23 16:37         ` David Presotto

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=ed8f1e8a629e33c8977cad10aa9684f0@terzarima.net \
    --to=forsyth@terzarima.net \
    --cc=9fans@cse.psu.edu \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).