Messages in this thread | | | Date | Fri, 15 Feb 2008 10:00:28 -0800 | From | "Dan Gora" <> | Subject | Re: PCI Bursting with PIO |
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On Fri, Feb 15, 2008 at 5:02 AM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote: > > Is there any way to get PIO to burst over the PCI bus in the read and > > write direction? My device has 4 BAR registers, but the area where I > > I think you are doign about as well as the X folks did when they spent > time on trying to optimise pio transfers to and from graphics card RAM. >
That's good to know. Do you have a link or anything to their discussion or some key words that I could hunt it down?
> > > Any ideas would be really appreciated, > > Put a DMA controller on it ;)
Ugh.. sadly that's what's coming. I really don't get why the northbridge cannot burst however. If the memory is mapped prefetchable and you have to do a PCI read through 3 PCIe bridges to finally get to your device it seems like it would _really_ behoove the bridge to do a Memory read multiple and get the whole cache line. I have searched around a lot and there doesn't seem to be any info at all on how you can persuade these bridges to do different PCI commands or burst. I don't know why....
thanks again for your help,
dan
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