[336] in linux-scsi channel archive
NCR53c810 Linux driver syncronous bug
daemon@ATHENA.MIT.EDU (Drew Eckhardt)
Tue Jul 11 18:54:13 1995
To: ncr53c810@colorado.edu, linux-scsi@vger.rutgers.edu
Date: Mon, 10 Jul 1995 10:59:04 -0600
From: Drew Eckhardt <drew@poohsticks.org>
If you look in drivers/scsi/53c7,8xx.h,
#define SXFER_TP_SHIFT 4
should be
#define SXFER_TP_SHIFT 5
The net effects of this bug are that the NCR chip talks to < 5M/sec drives
faster than they've said we can. In most cases, SCSI-I devices will claim
5M/sec support, in which case you get no error (the value is biased by 4, so
0 is used for the TP field in this case); if they're a bit slower, you may
see a 20% error.
This fix will be in the rel9 patch, which will probably also include
disconnect/reconnect support (My Maxtor, Syquests, and tape drive
disconnect/reconnect fine now, but something bogus is happening with
my RZ55).
