Messages in this thread | | | Date | Thu, 15 Jan 2009 08:54:00 -0800 | From | Ira Snyder <> | Subject | Re: [PATCH RFC v5] net: add PCINet driver |
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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
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