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Commit 762f007b authored by Jarek Poplawski's avatar Jarek Poplawski Committed by Greg Kroah-Hartman
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USB: fix cdc-acm problems with hard irq? (inconsistent lock state) 



Signed-off-by: default avatarJarek Poplawski <jarkao2@o2.pl>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent a7a0c9cd

drivers/usb/class/cdc-acm.c

+13 −13
Original line number Diff line number Diff line
@@ -325,7 +325,7 @@ static void acm_rx_tasklet(unsigned long _acm) 
	struct acm_rb *buf;

	struct tty_struct *tty = acm->tty;

	struct acm_ru *rcv;

	//unsigned long flags;

	unsigned long flags;

	int i = 0;

	dbg("Entering acm_rx_tasklet");
@@ -333,15 +333,15 @@ static void acm_rx_tasklet(unsigned long _acm) 
		return;



next_buffer:

	spin_lock(&acm->read_lock);

	spin_lock_irqsave(&acm->read_lock, flags);

	if (list_empty(&acm->filled_read_bufs)) {

		spin_unlock(&acm->read_lock);

		spin_unlock_irqrestore(&acm->read_lock, flags);

		goto urbs;

	}

	buf = list_entry(acm->filled_read_bufs.next,

			 struct acm_rb, list);

	list_del(&buf->list);

	spin_unlock(&acm->read_lock);

	spin_unlock_irqrestore(&acm->read_lock, flags);



	dbg("acm_rx_tasklet: procesing buf 0x%p, size = %d", buf, buf->size);
@@ -356,29 +356,29 @@ next_buffer: 
		memmove(buf->base, buf->base + i, buf->size - i);

		buf->size -= i;

		spin_unlock(&acm->throttle_lock);

		spin_lock(&acm->read_lock);

		spin_lock_irqsave(&acm->read_lock, flags);

		list_add(&buf->list, &acm->filled_read_bufs);

		spin_unlock(&acm->read_lock);

		spin_unlock_irqrestore(&acm->read_lock, flags);

		return;

	}

	spin_unlock(&acm->throttle_lock);



	spin_lock(&acm->read_lock);

	spin_lock_irqsave(&acm->read_lock, flags);

	list_add(&buf->list, &acm->spare_read_bufs);

	spin_unlock(&acm->read_lock);

	spin_unlock_irqrestore(&acm->read_lock, flags);

	goto next_buffer;



urbs:

	while (!list_empty(&acm->spare_read_bufs)) {

		spin_lock(&acm->read_lock);

		spin_lock_irqsave(&acm->read_lock, flags);

		if (list_empty(&acm->spare_read_urbs)) {

			spin_unlock(&acm->read_lock);

			spin_unlock_irqrestore(&acm->read_lock, flags);

			return;

		}

		rcv = list_entry(acm->spare_read_urbs.next,

				 struct acm_ru, list);

		list_del(&rcv->list);

		spin_unlock(&acm->read_lock);

		spin_unlock_irqrestore(&acm->read_lock, flags);



		buf = list_entry(acm->spare_read_bufs.next,

				 struct acm_rb, list);
@@ -400,9 +400,9 @@ urbs: 
		   free-urbs-pool and resubmited ASAP */

		if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {

			list_add(&buf->list, &acm->spare_read_bufs);

			spin_lock(&acm->read_lock);

			spin_lock_irqsave(&acm->read_lock, flags);

			list_add(&rcv->list, &acm->spare_read_urbs);

			spin_unlock(&acm->read_lock);

			spin_unlock_irqrestore(&acm->read_lock, flags);

			return;

		}

	}