Re: PCIe device driver question

From: Alan Cox
Date: Wed Jul 30 2008 - 13:13:19 EST


On Wed, 30 Jul 2008 09:09:36 -0700 (PDT)
Sanka Piyaratna <cesanka@xxxxxxxxx> wrote:

> Hi Alan,
>
> Actually the failures occur at addresses lot higher than this range, I am noticing the failure at dma address 0x0000000037845000. This would be at around 900MB ?

For x86 we don't do anything special and if your hardware is flagging the
memory as absent perhaps you should consult the hardware/bridge
documentation firt ?

In some cases (over 4GB and 32bit DMA masks set) we will use the GART on
x86-64 but that will still see addresses below 4GB being sent to the
device.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/