Subject: kern/4464: disable selection of irq 9 for pcmcia subsystem?
To: None <gnats-bugs@gnats.netbsd.org>
From: Eric S. Hvozda <hvozda@helios.ack.org>
List: netbsd-bugs
Date: 11/10/1997 18:28:05
>Number:         4464
>Category:       kern
>Synopsis:       irq 9 causes problems on the Sager NP7500A
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 10 15:35:04 1997
>Last-Modified:
>Originator:     Eric S. Hvozda
>Organization:
	
>Release:        NetBSD 1.3_ALPHA supped on 9Nov97
>Environment:
	
System: NetBSD helios.ack.org 1.3_ALPHA NetBSD 1.3_ALPHA (HELIOS) #4: Mon Nov 10 17:46:11 EST 1997 root@:/usr/src/sys/arch/i386/compile/HELIOS i386


>Description:
	
	On Sager NP7500A and look alikes (this particular notebook
	is marketed under various names by VARs), irq 9 causes problems
	if the pcmcia subsystem attempts to use it.

	These problems range anywhere to configured, but unusable
	devices (with a D-Link DE-650 ethernet card and a
	Megahertz V.34 modem) to drivers hanging (with an Adaptec
	SlimSCSI card).  In all cases one can get to DDB and cleanly
	reboot however.
>How-To-Repeat:
	Try to use the pcmcia subsystem on a Sager NP7500A or lookalike
	and observe odd behavior and note that the subsystem is
	attempting to use irq 9 from the messages on the console.  

	If the system isn't using irq 9 (perhaps you don't have a 
	builtin sound blaster consuming irq 7, or only one pcmcia
	card) use PCIC_ISA_INTR_ALLOC_MASK appropriately in a
	kernel config file to force use of irq 9.
>Fix:
	
	Perhaps the best idea is to disable selection of irq 9
	in the pcmcia subsystem.  This could be done by altering the
	default value of PCIC_ISA_INTR_ALLOC_MASK in
	/sys/dev/isa/i82365_isa.c.  Currently it is set to 0xfbff, but
	a setting of 0xf9ff will disable both irq 9 and 10 (interestingly
	irq 10 is safe to use on the Sager NP7500A unlike the NEC
	Versa series).

	It's a toss up from my POV; if it's clearly documented how
	to change the behavior, perhaps we don't care.  However it could
	be a show stopper for installs.  Also it can also have the
	appearance that NetBSD doesn't support the Sager if someone
	is unlikely enough to have the pcmcia subsystem try to use irq 9.

	At any rate, the diabling of this irq isn't an issue on the
	Sager since 11 and 15 are still left for selection.
>Audit-Trail:
>Unformatted: