drivers/usb/class/cdc-acm.c patch kernel 2.6.31.-rc1
flat view
From: Weng, Wending <hidden>
Date: 2009-07-22 21:22:31
Subsystem:
the rest, usb acm driver, usb subsystem · Maintainers:
Linus Torvalds, Oliver Neukum, Greg Kroah-Hartman
From 39e8558a114297ee9192f406d63f423aded05288 Mon Sep 17 00:00:00 2001
From: root <root@SBC_PC_3.localdomain> 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 <redacted> --- 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