[ofw][patch][ibal] make IBBUS start up synchronous.

[Leonid Keller]

What about the following implementation ?
(The patch adds an event field to CI_CA object, and post the event at
the end of the callback (__pnp_process_add_ca).

Index: core/al/al_ci_ca.h
===================================================================
--- core/al/al_ci_ca.h	(revision 4194)
+++ core/al/al_ci_ca.h	(working copy)
@@ -103,6 +103,9 @@
 	/* Array of port GUIDs on this CI CA. */
 	ib_net64_t					*port_array;
 
+	/* "end of PnP handling" event */
+	cl_event_t					event;
+
 }	al_ci_ca_t;
 
 
Index: core/al/kernel/al_ci_ca.c
===================================================================
--- core/al/kernel/al_ci_ca.c	(revision 4194)
+++ core/al/kernel/al_ci_ca.c	(working copy)
@@ -112,6 +112,8 @@
 	cl_qlist_init( &p_ci_ca->shmid_list );
 	cl_qpool_construct( &p_ci_ca->event_pool );
 	p_ci_ca->verbs = *p_ci;
+	cl_event_construct( &p_ci_ca->event );
+	cl_event_init( &p_ci_ca->event, FALSE );
 
 	cl_status = cl_spinlock_init( &p_ci_ca->attr_lock );
 	if( cl_status != CL_SUCCESS )
Index: core/al/kernel/al_pnp.c
===================================================================
--- core/al/kernel/al_pnp.c	(revision 4193)
+++ core/al/kernel/al_pnp.c	(working copy)
@@ -994,6 +994,7 @@
 
 	/* Cleanup the event record. */
 	deref_al_obj( &gp_pnp->obj );
+	cl_event_signal( &p_event_rec->p_ci_ca->event );
 	cl_free( p_event_rec );
 
 	AL_EXIT( AL_DBG_PNP );
@@ -1152,7 +1153,6 @@
 	cl_status_t			cl_status;
 	al_pnp_ca_event_t	*p_event_rec;
 	ib_ca_attr_t		*p_old_ca_attr;
-	uint32_t			ref_cnt, prev_cnt, i;
 
 	AL_ENTER( AL_DBG_PNP );
 
@@ -1233,17 +1233,15 @@
 	}
 
 	/* Queue the event to the async processing manager. */
-	ref_cnt = ref_al_obj( &gp_pnp->obj );
+	ref_al_obj( &gp_pnp->obj );
 	cl_async_proc_queue( gp_async_pnp_mgr, &p_event_rec->async_item
);
 
 	/* wait up to 3 seconds for the end of event propagation 
 	It is needed for enabling quick HCA disable/enable scenarios. */
-	prev_cnt = ref_cnt - 1;
-	for ( i = 0; i < 30; ++i ) {
-		if (ref_cnt <= prev_cnt)
-			break;
-		cl_thread_suspend(100);
-	}
+	cl_status = cl_event_wait_on(
+		&p_ci_ca->event, 3000, AL_WAIT_ALERTABLE );
+	if (cl_status != CL_SUCCESS)
+		return IB_ERROR;
 
 	AL_EXIT( AL_DBG_PNP );
 	return IB_SUCCESS;









 

> -----Original Message-----
> From: Sean Hefty [mailto:sean.hefty at intel.com] 
> Sent: Wednesday, March 25, 2009 6:59 PM
> To: Leonid Keller; ofw at lists.openfabrics.org
> Subject: RE: [ofw][patch][ibal] make IBBUS start up synchronous.
> 
> >+ /* wait up to 3 seconds for the end of event propagation 
> It is needed 
> >+ for enabling quick HCA disable/enable scenarios. */ prev_cnt = 
> >+ ref_cnt - 1; for ( i = 0; i < 30; ++i ) {  if (ref_cnt <= prev_cnt)
> >+   break;
> >+  cl_thread_suspend(100);
> >+ }
> 
> We should use an actual event mechanism here, rather than spinning.
> 
> Also, I'm not a fan of
> 
> while/for (...)
> 	if (x)
> 		break;
> 
> just move 'x' into the while/for check.
> 
> - Sean
> 
>