Devicetree
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
To: Alan Cox <alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
Cc: linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.org,
	"Hans J. Koch" <hjk-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	devicetree-discuss-mnsaURCQ41sdnm+yROfE0A@public.gmane.org,
	Greg KH <gregkh-l3A5Bk7waGM@public.gmane.org>
Subject: Re: [PATCH 2/2] uio: add an of_genirq driver
Date: Mon, 15 Jun 2009 19:45:39 +1000	[thread overview]
Message-ID: <1245059139.12400.4.camel@pasglop> (raw)
In-Reply-To: <20090615001207.1829e7b5-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>

On Mon, 2009-06-15 at 00:12 +0100, Alan Cox wrote:
> > > +	if (!uioinfo->irq)
> > > +		uioinfo->irq = UIO_IRQ_NONE;
> > 
> > Please don't do this. It's inconsistent if all other UIO drivers require
> > people to use UIO_IRQ_NONE and you also allow zero. UIO_IRQ_NONE was
> > introduced because 0 may be a legal interrupt number on some platforms.
> 
> Zero is not a valid IRQ number in the kernel (except in arch specific
> depths). IRQ numbers are also *unsigned* so -1 isn't a safe definition.
> 
> Zero means no IRQ. If any old UIO code is assuming otherwise it wants
> fixing.
> 
> It is the job of the platform to map a physical IRQ 0 to some other
> representation if it exists outside of arch specific code. This was
> decided some years ago and a large part of the kernel simply doesn't
> support any notion of a real IRQ 0.

Right, and powerpc complies with that rule, so 0 is fine for us.

Cheers,
Ben.

  parent reply	other threads:[~2009-06-15  9:45 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-12  0:04 [PATCH 0/2] add OF wrapper for uio-pdrv-genirq Wolfram Sang
     [not found] ` <1244765062-14144-1-git-send-email-w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2009-06-12  0:04   ` [PATCH 1/2] uio/pdrv_genirq: Refactor probe routine to expose a generic part Wolfram Sang
2009-06-14 12:15     ` Hans J. Koch
2009-06-12  0:04   ` [PATCH 2/2] uio: add an of_genirq driver Wolfram Sang
2009-06-14 12:21     ` Hans J. Koch
2009-06-14 17:14       ` Wolfram Sang
     [not found]         ` <20090614171406.GA1010-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2009-06-14 18:33           ` Hans J. Koch
2009-06-14 19:05             ` Wolfram Sang
     [not found]               ` <20090614190533.GA7387-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2009-06-14 19:23                 ` Hans J. Koch
2009-06-14 19:36                   ` Wolfgang Grandegger
     [not found]                     ` <4A355155.4020500-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2009-06-14 20:34                       ` Hans J. Koch
2009-06-14 22:00                         ` Wolfram Sang
     [not found]                           ` <20090614220022.GB24323-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2009-06-14 23:01                             ` Hans J. Koch
2009-06-14 23:46                               ` Wolfram Sang
     [not found]                                 ` <20090614234643.GA17791-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2009-06-14 23:50                                   ` Hans J. Koch
2009-06-14 19:27               ` Greg KH
     [not found]                 ` <20090614192707.GA11003-l3A5Bk7waGM@public.gmane.org>
2009-06-14 21:46                   ` Wolfram Sang
2009-06-14 23:12       ` Alan Cox
     [not found]         ` <20090615001207.1829e7b5-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
2009-06-14 23:45           ` Hans J. Koch
2009-06-15  8:44             ` Alan Cox
2009-06-15  9:45           ` Benjamin Herrenschmidt [this message]
     [not found]     ` <1244765062-14144-3-git-send-email-w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2009-06-14 14:40       ` Grant Likely
     [not found]         ` <fa686aa40906140740m43e9dd8am4d242310f681c95c-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-16  9:04           ` Wolfram Sang
2009-06-16 12:46             ` Grant Likely

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=1245059139.12400.4.camel@pasglop \
    --to=benh-xvmvhmargas8u2djnn8i7kb+6bgklq7r@public.gmane.org \
    --cc=alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org \
    --cc=devicetree-discuss-mnsaURCQ41sdnm+yROfE0A@public.gmane.org \
    --cc=gregkh-l3A5Bk7waGM@public.gmane.org \
    --cc=hjk-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linuxppc-dev-mnsaURCQ41sdnm+yROfE0A@public.gmane.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