USB: fix cdc-acm problems with hard irq? (inconsistent lock state)

Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 13 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index daecdf0bff0..9a9012fd284 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -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;
                 }
         }