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SCSI driver questions ..

To: linux-mips@fnet.fr
Subject: SCSI driver questions ..
From: Dave Airlie <airlied@csn.ul.ie>
Date: Fri, 14 May 1999 13:42:53 +0100 (IST)
Well I've been poking around, and looking around and all that, and /me
don't like SCSI drivers any more :-)

Anyways, question is

dma_init_read and dma_init_write are passed a __u32 vaddress, this is
resolving on my system for the first write to  00fe3000, however if I read
from this address I get a 

Unable to handle kernel paging request at virtual address 00fe3000

So what am I missing....??? do I need to do some conversion on this
address?

Further information on the DS5000/200 SCSI, the SCSI is a shared 128k
buffer, and there is no DMA to system memory, so I'm using PIO cmds, and
for data, writing is done by coping the data to the SRAM during the
dma_init_write function, and setting the DMA register to where the data
is, for read, I set the DMA register to an empty buffer in the SRAM, and
then (this bit is sick and twisted but should work for now.. :-), I use
dma_drain to copy the buffer back to the system memory from the DMA
region, after DMA has completed...

Of course I'm totally unsure of lots of things, like cfreq and stuff, but
I shall battle onwards ...

Dave.



------------ David Airlie, David.Airlie@ul.ie,airlied@skynet --------
Telecommunications Research Centre, ECE Dept, University of Limerick \
http://www.csn.ul.ie/~airlied   -- Telecommunications Researcher      \
--- TEL: +353-61-202695 -----------------------------------------------

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