All of lore.kernel.org
 help / color / mirror / Atom feed
From: Rogier Wolff <R.E.Wolff@BitWizard.nl>
To: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: IRQ number question.
Date: Mon, 3 Sep 2018 21:24:32 +0200	[thread overview]
Message-ID: <20180903192432.GE11854@BitWizard.nl> (raw)
In-Reply-To: <20180903190903.290fff01@alans-desktop>

On Mon, Sep 03, 2018 at 07:09:03PM +0100, Alan Cox wrote:
> On Mon, 3 Sep 2018 19:16:39 +0200

> > irq 18: nobody cared (try booting with the "irqpoll" option)
> > 
> > I've been writing device drivers in the past, but in the past
> > when the lspci listed "IRQ 14" then I'd have to request_irq (14, ...
> 
> The IRQ number in the PCI configuration space is just a label really for
> legacy OS stuff. Nothing actually routes interrupts according to it (*).
> If it's coming up as 14 that looks more like the BIOS mislabelled it.
> Legacy PCI interrupts care about lines and pins not irq numbers.
> 
> Are you looking at values after things like pci_enable_device were called
> or before ? Are you also looking at what is in pcidev->irq after the
> enable ?

The driver used to be for an ISA card. But as the ISA hardware is
becoming less and less available, things were in need of an upgrade.

So... So far I was just doing
  inmod  mydriver.ko pci=1 irq=14 io=0xae00 mem=0xfda00000

keeping most of the ISA driver. (for testing I was able to run the ISA
card with the upgraded driver that does the PCI card as well...

So io= is the address I got from lspci, mem= and irq= the
same. Apparently All of them are accurate except for the IRQ?

So the answer is: No I wasn't doing pci_enable_device. I guess I'll 
have to make a proper PCI driver then. Hmm. OK. I'll look into it. 

	Roger. 

-- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 **
**    Delftechpark 26 2628 XH  Delft, The Netherlands. KVK: 27239233    **
*-- BitWizard writes Linux device drivers for any device you may have! --*
The plan was simple, like my brother-in-law Phil. But unlike
Phil, this plan just might work.

  reply	other threads:[~2018-09-03 19:24 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-03 17:16 IRQ number question Rogier Wolff
2018-09-03 18:09 ` Alan Cox
2018-09-03 19:24   ` Rogier Wolff [this message]
2018-09-04  7:40   ` Rogier Wolff

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=20180903192432.GE11854@BitWizard.nl \
    --to=r.e.wolff@bitwizard.nl \
    --cc=gnomes@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@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.