linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: David Woodhouse <dwmw2@infradead.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Brownell <david-b@pacbell.net>,
	Bertrand Baudet <bbaudet@lacie.com>, Greg KH <greg@kroah.com>,
	linux-usb-devel@lists.sourceforge.net,
	linuxppc-embedded@lists.linuxppc.org
Subject: Re: [linux-usb-devel] Re: RE : MPC5200Lite PCI & IRQ
Date: Sun, 27 Jun 2004 11:09:07 +0100	[thread overview]
Message-ID: <1088330947.4268.8.camel@localhost.localdomain> (raw)
In-Reply-To: <1088258564.3007.8.camel@localhost.localdomain>


On Sat, 2004-06-26 at 15:02 +0100, Alan Cox wrote:
> There are a lot of drivers that assume 0 means no IRQ, including some
> big x86 non-PC systems. Remember however that dev->irq is an OS private
> cookie. In the x86 case for example we add 16 to APIC directed
> interrupts both to split IRQs out and to avoid this problem.

There aren't _that_ many drivers which have this bug; certainly not
non-ISA drivers. Even when you consider irq_t to be an OS-private
cookie, that doesn't excuse this brokenness on the part of drivers --
they need fixing.

> So if your board has an IRQ 0 and it is a problem - just change your
> numbering scheme.

That's a workaround, not a fix. Not really Linux style.

Personally, I think we want to stop even thinking of it as a numbering
scheme. IRQs are a tree, not a flat array.

--
dwmw2


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

      reply	other threads:[~2004-06-27 10:09 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-06-18 10:06 RE : MPC5200Lite PCI & IRQ Bertrand Baudet
2004-06-18 10:20 ` David Woodhouse
2004-06-19  0:01   ` Greg KH
2004-06-26 14:24     ` [linux-usb-devel] " David Brownell
2004-06-26 14:02       ` Alan Cox
2004-06-27 10:09         ` David Woodhouse [this message]

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=1088330947.4268.8.camel@localhost.localdomain \
    --to=dwmw2@infradead.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=bbaudet@lacie.com \
    --cc=david-b@pacbell.net \
    --cc=greg@kroah.com \
    --cc=linux-usb-devel@lists.sourceforge.net \
    --cc=linuxppc-embedded@lists.linuxppc.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 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).