On Tue, 3 Apr 2007, Michael L. Hitch wrote:

>  OK, the change that made the le0 device not be detected was revision 1.109 
> of sys/kern/kern_malloc.c.  That change was to make it use mutexes.
> That change also tripped over a bug in the vax implementation of 
> mutex_spin_{enter,exit} that I've been looking into.
>
>  In the meantime, a workaround is to build with LOCKDEBUG (which doesn't
> include the vax-specific mutex implementations).
>
>  That should get the network interface going, but -current (sometime after 
> March 24) has something that causes the kernel to spend most of its time in 
> the kernel.  I'm working on narrowing down when that occurred now.

   OK, there appears to be two bugs that cause this:
     1. The ci_mtx_count in cpu_info doesn't get initialized, so
        mutex_spin_enter() never saves the initial IPL value, and
        mutex_spin_exit() never restores the [unsaved] IPL and remains
        running at the IPL level specified in the mutex.
     2. Even if ci_mtx_count had gotten initialized properly,
        mutex_spin_enter() wouldn't have saved the original IPL value.

   I have been using these changes that appear to make it work correctly, 
at least as far as configuring the vsbus devices.

Index: sys/arch/vax/include/mutex.h
===================================================================
RCS file: /cvsroot/src/sys/arch/vax/include/mutex.h,v
retrieving revision 1.7
diff -u -r1.7 mutex.h
--- sys/arch/vax/include/mutex.h	12 Mar 2007 02:22:43 -0000	1.7
+++ sys/arch/vax/include/mutex.h	6 Apr 2007 00:42:53 -0000
@@ -82,6 +82,10 @@
   * an interlocking step.
   */

+#ifndef LOCKDEBUG
+#define	MUTEX_COUNT_BIAS		1
+#endif
+
  #ifndef __MUTEX_PRIVATE

  struct kmutex {
@@ -111,10 +115,6 @@
  #define	__HAVE_MUTEX_STUBS		1
  #define	__HAVE_SPIN_MUTEX_STUBS		1

-#ifndef LOCKDEBUG
-#define	MUTEX_COUNT_BIAS		1
-#endif
-
  static inline uintptr_t
  MUTEX_OWNER(uintptr_t owner)
  {
Index: sys/arch/vax/vax/lock_stubs.S
===================================================================
RCS file: /cvsroot/src/sys/arch/vax/vax/lock_stubs.S,v
retrieving revision 1.3
diff -u -r1.3 lock_stubs.S
--- sys/arch/vax/vax/lock_stubs.S	12 Mar 2007 02:22:43 -0000	1.3
+++ sys/arch/vax/vax/lock_stubs.S	6 Apr 2007 00:42:53 -0000
@@ -92,7 +92,9 @@
  	mtpr	%r3, $PR_IPL			/*   yes, raise IPL */
  1:	mfpr	$PR_SSP, %r1			/* get curcpu */
  	sobgeq	CI_MTX_COUNT(%r1), 2f		/* decr mutex count */
-	movl	%r2, CI_MTX_OLDSPL(%r1)		/*   save was-current IPL */
+	brb	4f
+2:	movl	%r2, CI_MTX_OLDSPL(%r1)		/*   save was-current IPL */
+4:
  #if defined(DIAGNOSTIC) || defined(MULTIPROCESSOR)
  	bbssi	$0, (%r0), 3f			/* take out mutex */
  	ret

--
Michael L. Hitch			mhitch@montana.edu
Computer Consultant
Information Technology Center
Montana State University	Bozeman, MT	USA