>Number:         22100
>Category:       kern
>Synopsis:       kernel trap due to `unexpected play intr' in cs4281 driver
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jul 09 03:06:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Brian de Alwis
>Release:        NetBSD 1.6U
>Organization:
>Environment:
System: NetBSD slab 1.6U NetBSD 1.6U (GENERIC_LAPTOP) #0: Thu Jul 3 12:36:07 UTC 2003 autobuild@tgm.daemon.org:/autobuild/HEAD/i386/OBJ/autobuild/HEAD/src/sys/arch/i386/compile/GENERIC_LAPTOP i386
Architecture: i386
Machine: i386
>Description:
	For some reason, galeon died on my machine, and as a result
	any access to the file system causes the process to freeze.
	While this is not the subject of this PR, it is the only
	time I've seen the symptoms described below.

	Rebooting from DDB (`reboot'), the kernel boots, but a kernel
	fault occurs (the following was cribbed by hand, and might have
	some minor errors):

apm0 at mainbus0: Power Management spec V1.2
unexpected play intr
uvm_fault(0xc056d140, 0, 0, 1) -> 0xe
kernel: pagefault trap, code=0
Stopped in pid 0.1 (swapper) at netbsd: cs4281_intr+0x108: movl 0x4(%eax),%eax

	Doing a `bt' shows:

cs4281_intr+0x108
Xintr_legacy10
----

	(I failed to record the rest)

	Using objdump, this corresponds to the following code:

/usr/src/sys/arch/i386/compile/GENERIC_LAPTOP/../../../../dev/pci/cs4281.c:349
                empty_dma = sc->sc_pdma->addr;
     3f9:       8b 43 7c                mov    0x7c(%ebx),%eax
     3fc:       8b 40 04                mov    0x4(%eax),%eax


>How-To-Repeat:
	Unfortunately, this is difficult.  (Or perhaps this is
	fortunate :-) I have only seen this when galeon crashes --
	which it does for some unfortunate reason.

>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted: