Re: yenta-socket oops with 2.5.73-mm3, 2.5.74, 2.5.74-mm1

[Russell King <rmk@arm.linux.org.uk>]

On Sun, Jul 06, 2003 at 12:39:34AM +0200, Daniel Ritz wrote:
> problem is that an interrupt arrives before socket->thread_wait is
> initialized so we crash in __wake_up_common. i think source of the
> interrupt is socket_init called before the initialization. but an
> interrupt can still arrive before...

I suspect that even with your patch below, there is the posibility
to receive an unintentional call into pcmcia_parse_events() from some
socket drivers.  The all round better fix is to make pcmcia_parse_events()
ignore socket change events until the socket thread is up and running.

Nevertheless, the patch looks correct, so I am still interested in
whether your patch helps solve Michael's problem.

> michael, can you try this one?

Daniel's patch:

--- 1.50/drivers/pcmcia/cs.c	Mon Jun 30 22:22:30 2003
+++ edited/cs.c	Sat Jul  5 23:58:07 2003
@@ -338,13 +338,13 @@
 	socket->erase_busy.next = socket->erase_busy.prev = &socket->erase_busy;
 	INIT_LIST_HEAD(&socket->cis_cache);
 	spin_lock_init(&socket->lock);
-
-	init_socket(socket);
-
 	init_completion(&socket->thread_done);
 	init_waitqueue_head(&socket->thread_wait);
 	init_MUTEX(&socket->skt_sem);
 	spin_lock_init(&socket->thread_lock);
+
+	init_socket(socket);
+
 	ret = kernel_thread(pccardd, socket, CLONE_KERNEL);
 	if (ret < 0)
 		return ret;

and my patch (may apply with some offset, which I'm about to check
into bk anyway):

--- linux/drivers/pcmcia/cs.c.old	Fri Jul  4 10:21:50 2003
+++ linux/drivers/pcmcia/cs.c	Sun Jul  6 23:04:10 2003
@@ -870,11 +870,13 @@
 
 void pcmcia_parse_events(struct pcmcia_socket *s, u_int events)
 {
-	spin_lock(&s->thread_lock);
-	s->thread_events |= events;
-	spin_unlock(&s->thread_lock);
+	if (s->thread) {
+		spin_lock(&s->thread_lock);
+		s->thread_events |= events;
+		spin_unlock(&s->thread_lock);
 
-	wake_up(&s->thread_wait);
+		wake_up(&s->thread_wait);
+	}
 } /* pcmcia_parse_events */
 
 

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html