USG 4.0 general disk driver bug(?)

[jhl at tty3b.UUCP]

	We are running UNIX 4.0 on PDP-11/70's with RP06 disk drives
on an RH70 controller.  We recently got an ML11 RAM disk unit installed,
and consequently made the switch from the standard `hp' driver to the
`gd' general disk driver, which supports RP06's as well as ML11's.
The ML11 seems to work fine, but now we are having problems with the
RP06's.  We first noticed that something was wrong when our /usr file
system ran out of space; it turned out that /usr/adm/errfile had suddenly
grown to over a megabyte.  Errpt showed that an error had been logged every
few seconds by the controller for the RP06's, and for each one logged,
40 or 50 THOUSAND had gone unrecorded.  Turning off the error demon
has so far `solved' the problem -- we don't get a humongous errfile (and
system performance doesn't seem to be greatly affected) -- but of course
now we don't get any error logging at all.
	I tried looking at the source code to see where the error was
recognized and logged, but I couldn't tell for sure what was going on.
However, by comparing gd.c to hp.c, I noticed that in the interrupt
routines (gdintr/hpintr) there was a difference in the logic of the
else clause after the first if:
(gd.c)
	} else {
		rp->cs1 = IE;
		...
(hp.c)
	} else {
		if (as == 0)
			rp->hpcs1 = IE;
		...
Is it a bug to enable interrupts unconditionally, and could this be
the cause of our problem?
	Any help would be greatly appreciated.

					Jonathon Luers
					Teletype Corporation
					...ihnp4!tty3b!jhl