Subject: Re: SCSI tape problem
To: Michael L. Hitch <email@example.com>
From: Ignatios Souvatzis <firstname.lastname@example.org>
Date: 04/18/1998 19:42:24
On Fri, Apr 17, 1998 at 09:12:18PM -0600, Michael L. Hitch wrote:
> The block limits seem rather strange - I'd suspect they are probably
> garbage. The buffer for the block limits doesn't appear to be cleared
> and the actual length of the data returned doesn't appear to be checked,
> so it's possible that those values are garbage left on the stack. More
> likely, the buffer is not on a long word boundary and is six bytes long,
> and I suspect the driver is not getting the DMA data transferred properly.
This is highly probable.
As far as I know, the DMA hardware of the Fastlane uses an internal fifo which
is automatically cleared on each setup.
So it is not possible to correctly transfer odd-sized blocks to unaligned
buffers doing multi-segment magic... you have to poll them, or bounce buffer
the WHOLE transfer.
Other P5 boards dont have this limitations.