From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3C21B464.4030509@humboldt.co.uk> Date: Thu, 20 Dec 2001 09:50:28 +0000 From: Adrian Cox MIME-Version: 1.0 To: "David =?ISO-8859-1?Q?M=FCller?= (ELSOFT AG)" Cc: linuxppc-dev@lists.linuxppc.org Subject: Re: ISA DMA References: <3C206A41.1080501@humboldt.co.uk> <3C21A301.2080204@elsoft.ch> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: David Müller (ELSOFT AG) wrote: > Seems like you are facing the same problem as i do. But IIRC i think you > have to adjust the code in include/asm/dma.h (and possibly other places) > as well (at least in 2.4.14, not sure about the later kernels). The main problem I can see is that the code always writes to the DMA_HI_PAGE_x registers, irrespective of whether they actually exist. This should be harmless, as nothing else is mapped to those locations. > What south bridge do you use? Some of the newer ones offer 32bit > addressing capability for DMA. Via686a. As I understand it, 32-bit DMA uses the DMA_HI_PAGE_x registers from 0x487 to 0x48a, and the Via manual doesn't claim to have any registers in that range. The only 32-bit DMA southbridge I've encountered is the Winbond chip on the Sandpoint, and that chip doesn't have UDMA66, USB, and audio. -- Adrian Cox http://www.humboldt.co.uk/ ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/