>From 39e8558a114297ee9192f406d63f423aded05288 Mon Sep 17 00:00:00 2001
From: root <root@xxxxxxxxxxxxxxxxxxxx>
Date: Tue, 21 Jul 2009 10:48:15 -0400
vers/usb/class/cdc-acm.cSubject: [PATCH] When the usb-serial cable is unpluged, the usb host controller driver returns all scheduled URBs to usb-serial driver(cdc-acm.c), and the usb-serial driver(cdc-acm.c) doesn't detect this exception, continues to schedule the URBs, it causes a dead loop.
This change fixes this problem.
Signed-off-by: Wending Weng <wweng@xxxxxxxxxxxxxx>
---
drivers/usb/class/cdc-acm.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 38bfdb0..3cc3e18 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -372,8 +372,15 @@ static void acm_read_bulk(struct urb *urb)
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add(&buf->list, &acm->spare_read_bufs);
spin_unlock(&acm->read_lock);
- /* nevertheless the tasklet must be kicked unconditionally
- so the queue cannot dry up */
+
+ /* Normally, the tasklet must be kicked unconditionally
+ so the queue cannot dry up, however, if the cable is disconnected,
+ or whatever fatal error, it must not reschedule any URB */
+
+ // Stop rescheduling any URB in case the connection is shutdown
+ if ((urb->status == -ESHUTDOWN) || (urb->status == -EPROTO))
+ return;
+
}
if (likely(!acm->susp_count))
tasklet_schedule(&acm->urb_task);
--
1.5.2.1
--
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