Date: Thu, 31 Aug 2006 20:22:36 -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
Message-ID: <20060901032236.GB336@kroah.com>
References: <20060830062338.GA10285@kroah.com> <20060830143410.GB19477@gate.crashing.org> <20060830175529.GB6258@kroah.com> <44F78E88.8050602@myri.com>
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On Thu, Aug 31, 2006 at 09:36:08PM -0400, Brice Goglin wrote:
> I might be nice to have something like a copy-block where the
> application writes/reads data, while the device does DMA only from/to
> there. We would need an easy way to mmap some anonymous DMA-ready memory
> in user-space, and something to give the corresponding DMA addresses to
> the application.

Sure, send a patch :)

> 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.

thanks,

greg k-h
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