James Bottomley wrote:
> On Mon, 2004-06-21 at 03:41, Douglas Gilbert wrote:
> 
>>I just tested it in lk 2.6.7-bk2 and the advansys driver is
>>broken. The disk access light stays on for several seconds
>>while it tries to read the partition table after which it
>>announces "unknown partition table". Since my rootfs is on
>>that disk it's all downhill from there.
> 
> 
> To be sure: the inquiry goes through and produces the correct result,
> and the read capacity, but then the read partition table fails?
> 
> If so, I think that sounds like a failure in the use_sg != 0 path.

Here are some more datapoints. There are at least 3 categories
of adapters handled by the advansys driver:
   - ISA: broken in lk 2.6 series
   - PCI narrow (8 bit SCSI bus e.g. ABP-940U): working in 2.6.7-bk2
   - PCI wide (16 bit SCSI bus, e.g. ASB-3940U2W): broken in 2.6.7-bk2
     but was working in lk 2.6.7

By playing around with the U2W adapter I found that it does
work when use_sg==0 but the returned data becomes incorrect
30 bytes into the transfer when use_sg==2. It is almost as if
the scatter gather DMA kicks off ok then stalls taking
several seconds to complete (with no timeout).

This was tested with:
   sg_dd if=/dev/sg1 of=t bs=512 count=63
   sg_dd if=/dev/sg1 of=tt bs=512 count=65

Since the sg driver bypasses scatter gather when the transfer
is <= 32 KB then the first sg_dd works and the second one
fails as described above.

Any suggestions for further testing?

Attached is a small patch to bump the version number
and fix the compile error when ADVANSYS_DEBUG is
defined.

Doug Gilbert