Re: [Patch] DMA mapping API for Alpha

Ivan Kokshaysky
2003-04-29T12:11:38Z

On Tue, Apr 29, 2003 at 01:58:29PM +0200, Marc Zyngier wrote:
> That's exactly what I wanted to avoid : It we feed NULL (for a non PCI
> device) to pci_map_single (for example), we limit the max DMA address
> to 24 bits, and this is quite bad for an EISA device, which is 32 bits
> capable.

Agreed, but what if your EISA-PCI bridge has only 30 address lines wired
to PCI? Yes, we can check this for EISA device because it has *real*
PCI parent (thanks, Marc :-), but what about ISA/legacy/whatever drivers?
I doubt that all of them bother to set dma_mask pointer (so you can have
an oops there).

Ivan.