Subject: 53c825 differential vs. single-ended (was Re: 53c876 support (SCSI)?)
To: Matthew Jacob <mjacob@feral.com>
From: Michael K. Sanders <msanders@confusion.net>
List: current-users
Date: 08/17/1998 17:00:34
Okay, so I finally got the NCR controller and am now trying to get it
to work. The first problem is that the driver thinks it's a
single-ended controller, when it should be differential:
ncr0 at pci0 dev 9 function 0: ncr 53c825 fast10 wide scsi
ncr0: interrupting at irq 12
ncr0: minsync=25, maxsync=206, maxoffs=8, 16 dwords burst, normal dma
fifo
ncr0: single-ended, open drain IRQ driver
ncr0: restart (scsi reset).
Looking at ncr.c, it seems that the differential test is commented
out:
#ifdef SCSI_NCR_SYMBIOS_COMPAT
if (!(np->rv_gpcntl & 0x01))
np->features |= FE_LED0;
#if 0 /* Not safe enough without NVRAM support or user settable
option */
if (!(INB(nc_gpreg) & 0x08))
np->features |= FE_DIFF;
#endif
#endif /* SCSI_NCR_SYMBIOS_COMPAT */
Will Bad Things happen if I uncomment that? Should I add FE_DIFF to
the flags below instead?
> {NCR_825_ID, 0x00, "ncr 53c825 fast10 wide scsi", 4, 8, 4,
> FE_WIDE|FE_ERL|FE_BOF}