Re: PROBLEM: usb not working with 2.4.8-ac8

[Pete Zaitcev]

> Looks like the change int he usb_start_wait_urb code is a problem. 

Yes, something was not right with my change.
I am trying to coax people into testing this (on top of -ac8):

--- linux-2.4.8-ac8/drivers/usb/usb.c	Tue Aug 21 14:39:55 2001
+++ linux-2.4.8-ac8-niph/drivers/usb/usb.c	Tue Aug 21 16:02:01 2001
@@ -1080,10 +1080,17 @@
 	current->state = TASK_RUNNING;
 	remove_wait_queue(&awd.wqh, &wait);
 
-	if (!timeout) {
-		printk("usb_control/bulk_msg: timeout\n");
-		usb_unlink_urb(urb);  // remove urb safely
-		status = -ETIMEDOUT;
+	if (!awd.done) {
+		if (urb->status != -EINPROGRESS) {	/* No callback?!! */
+			printk(KERN_ERR "usb: raced timeout, "
+			    "pipe 0x%x status %d time left %d\n",
+			    urb->pipe, urb->status, timeout);
+			status = urb->status;
+		} else {
+			printk("usb_control/bulk_msg: timeout\n");
+			usb_unlink_urb(urb);  // remove urb safely
+			status = -ETIMEDOUT;
+		}
 	} else
 		status = urb->status;
 

> I suspect either you need to add wmb() and rmb() to stop misoptimisations
> on done (along with making it (!timeout && !awd.done)

Arjan said so too - I'll add them later just in case.
About (!timeout && !awd.done) - it's not going to be enough,
I think. I suspect that callback is not delivered at all
in some circumstances, or something really screwy like that.

> there is a signal related problem - if so  making it set the state
> to TASK_UNINTERRUPTIBLE might cure it

I tried that first and it worked, but someone disagreed. Dunno...

-- Pete