Devicetree
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: devicetree-discuss@ozlabs.org, "Hans J. Koch" <hjk@linutronix.de>,
	linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
	Greg KH <gregkh@suse.de>
Subject: Re: [PATCH 2/2] uio: add an of_genirq driver
Date: Mon, 15 Jun 2009 00:12:07 +0100	[thread overview]
Message-ID: <20090615001207.1829e7b5@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <20090614122136.GD3639@local>

> > +	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.

Alan

  parent reply	other threads:[~2009-06-14 23:12 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 [this message]
     [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
     [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

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