From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 9 Jan 02 09:53:06 PST From: msokolov@ivan.Harhan.ORG (Michael Sokolov) Message-Id: <0201091753.AA22414@ivan.Harhan.ORG> To: linuxppc-dev@lists.linuxppc.org Subject: Re: ISA DMA take 2 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Adrian Cox wrote: > Yes - and I set ISA_DMA_THRESHOLD to 0x00ffffff. It's not possible to > use ISA DMA with the Via southbridge unless you have main memory at 0x0 > on the PCI bus. As I understand it, you also have to have no I/O hole in the mapping of the bottom 16 MB of memory onto PCI, right? As I understand it, Linux/PPC is a sane PPC OS and treats all PPC memory as normal, without any special treatment for 0xA0000-0xFFFFF, so your DMA buffer could legitimately end up in that region and if your memory map has an I/O hole you would be screwed, right? And of course main memory on PCI at 0 with no I/O hole means you can't have video on the same PCI bus... !@#$ing pee sea legacy :( MS ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/