Date: Thu, 31 Aug 2006 21:27:50 -0700
From: Greg KH <greg@kroah.com>
To: Brice Goglin <brice@myri.com>
Cc: Matt Porter <mporter@embeddedalley.com>, linux-kernel@vger.kernel.org,
       Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC] Simple userspace interface for PCI drivers
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On Thu, Aug 31, 2006 at 11:37:58PM -0400, Brice Goglin wrote:
> Greg KH wrote:
> >> Additionally, the current code might not be flexible enough regarding
> >> acknowledging of interrupts. It might be good to use the bit that PCI
> >> 2.2 defines in the config space to mask/unmask interrupt in a generic
> >> way. Something like : when an interrupt comes, the driver mask the
> >> interrupts using this bit, and then passes the event to user-space. The
> >> user-space interrupt handler acknowledges the interrupt with the device
> >> specific code, and then unmask with the PCI 2.2 bit.
> >>     
> >
> > You can do that today with this code.  Remember, you have to have a
> > tiny kernelspace portion of your driver to handle the interrupt.  You
> > can do whatever you want in that interrupt handler.
> >   
> 
> The whole point of masking interrupt with this config-space bit is that
> we might not need any tiny kernelspace portion for our driver anymore.
> It won't work for devices that are not PCI 2.2 compliant. But, it might
> be good for the ones that are?

I don't really know.  I think 2.2 PCI devices might still be a bit rare,
but do not know for sure.

thanks,

greg k-h
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