From: Ira Snyder <iws@ovro.caltech.edu>
To: Arnd Bergmann <arnd@arndb.de>
Cc: netdev@vger.kernel.org, Rusty Russell <rusty@rustcorp.com.au>,
linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
shemminger@vyatta.com, David Miller <davem@davemloft.net>
Subject: Re: [PATCH RFC v5] net: add PCINet driver
Date: Thu, 15 Jan 2009 08:54:00 -0800 [thread overview]
Message-ID: <20090115165359.GA2230@ovro.caltech.edu> (raw)
In-Reply-To: <200901151358.34250.arnd@arndb.de>
On Thu, Jan 15, 2009 at 01:58:33PM +0100, Arnd Bergmann wrote:
> On Thursday 15 January 2009, Ira Snyder wrote:
>
> > The only problem with that is that you cannot route interrupts from the
> > DMA controller over PCI with the PowerPC core running. Which makes it
> > mostly useless for this case.
>
> If the host supports MSI, you can simply program the DMA controller to
> write the correct message to the inbound address of the MSI interrupt
> controller!
>
> All modern host systems should have MSI, as this is required by the
> PCIe specification, but it still somewhat limits the choice of your
> hosts.
>
These are PCI boards, not PCIe. The host computers are all Pentium3-M
systems. I tried enabling MSI on the Freescale boards in the driver, by
calling pci_enable_msi() during probe(), and it failed. I'm pretty sure
I can't do MSI.
I'll keep thinking about how to manage the DMA. Feel free to toss around
any ideas you have, though.
Ira
WARNING: multiple messages have this Message-ID (diff)
From: Ira Snyder <iws@ovro.caltech.edu>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
David Miller <davem@davemloft.net>,
linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
shemminger@vyatta.com, netdev@vger.kernel.org
Subject: Re: [PATCH RFC v5] net: add PCINet driver
Date: Thu, 15 Jan 2009 08:54:00 -0800 [thread overview]
Message-ID: <20090115165359.GA2230@ovro.caltech.edu> (raw)
In-Reply-To: <200901151358.34250.arnd@arndb.de>
On Thu, Jan 15, 2009 at 01:58:33PM +0100, Arnd Bergmann wrote:
> On Thursday 15 January 2009, Ira Snyder wrote:
>
> > The only problem with that is that you cannot route interrupts from the
> > DMA controller over PCI with the PowerPC core running. Which makes it
> > mostly useless for this case.
>
> If the host supports MSI, you can simply program the DMA controller to
> write the correct message to the inbound address of the MSI interrupt
> controller!
>
> All modern host systems should have MSI, as this is required by the
> PCIe specification, but it still somewhat limits the choice of your
> hosts.
>
These are PCI boards, not PCIe. The host computers are all Pentium3-M
systems. I tried enabling MSI on the Freescale boards in the driver, by
calling pci_enable_msi() during probe(), and it failed. I'm pretty sure
I can't do MSI.
I'll keep thinking about how to manage the DMA. Feel free to toss around
any ideas you have, though.
Ira
next prev parent reply other threads:[~2009-01-15 16:54 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-07 19:50 [PATCH RFC v5] net: add PCINet driver Ira Snyder
2009-01-07 19:50 ` Ira Snyder
2009-01-08 19:16 ` David Miller
2009-01-08 19:16 ` David Miller
2009-01-08 19:16 ` David Miller
2009-01-08 19:27 ` Ira Snyder
2009-01-08 19:27 ` Ira Snyder
2009-01-08 21:51 ` Ira Snyder
2009-01-10 23:32 ` Benjamin Herrenschmidt
2009-01-10 23:32 ` Benjamin Herrenschmidt
2009-01-12 17:56 ` Arnd Bergmann
2009-01-12 17:56 ` Arnd Bergmann
2009-01-13 2:32 ` Rusty Russell
2009-01-13 2:32 ` Rusty Russell
2009-01-13 3:34 ` Ira Snyder
2009-01-13 3:34 ` Ira Snyder
2009-01-13 16:33 ` Arnd Bergmann
2009-01-13 16:33 ` Arnd Bergmann
2009-01-13 16:40 ` Ira Snyder
2009-01-13 16:40 ` Ira Snyder
2009-01-13 17:42 ` Arnd Bergmann
2009-01-13 17:42 ` Arnd Bergmann
2009-01-15 0:12 ` Ira Snyder
2009-01-15 0:12 ` Ira Snyder
2009-01-15 12:58 ` Arnd Bergmann
2009-01-15 12:58 ` Arnd Bergmann
2009-01-15 16:54 ` Ira Snyder [this message]
2009-01-15 16:54 ` Ira Snyder
2009-01-15 17:53 ` Arnd Bergmann
2009-01-15 17:53 ` Arnd Bergmann
2009-01-15 18:20 ` Ira Snyder
2009-01-15 18:20 ` Ira Snyder
2009-01-15 20:57 ` Arnd Bergmann
2009-01-15 23:27 ` Ira Snyder
2009-01-15 23:27 ` Ira Snyder
2009-01-15 19:21 ` Ira Snyder
2009-01-15 19:21 ` Ira Snyder
2009-01-15 21:22 ` Arnd Bergmann
2009-01-15 21:22 ` Arnd Bergmann
2009-01-15 21:40 ` Ira Snyder
2009-01-15 21:40 ` Ira Snyder
2009-01-15 22:53 ` Arnd Bergmann
2009-01-15 22:53 ` Arnd Bergmann
2009-01-15 23:31 ` Ira Snyder
2009-01-15 23:31 ` Ira Snyder
2009-01-16 9:15 ` Jan-Bernd Themann
2009-01-16 9:15 ` Jan-Bernd Themann
2009-01-08 19:16 ` David Miller
2009-01-08 19:16 ` David Miller
-- strict thread matches above, loose matches on Subject: below --
2009-01-07 19:50 Ira Snyder
2009-01-07 19:50 Ira Snyder
2009-01-07 19:50 Ira Snyder
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