rt2x00: Don't queue ieee80211 work after USB removal

This prevents the rt2x00 driver from queueing ieee80211 work after the  
USB card has been removed, preventing a kernel panic.

Signed-off-by: Sean Cross <sean@chumby.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 17 insertions, 7 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 71761b343839..73bbec58341e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -815,6 +815,8 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
 
         mutex_init(&rt2x00dev->csr_mutex);
 
+        set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
+
         /*
          * Make room for rt2x00_intf inside the per-interface
          * structure ieee80211_vif.
@@ -871,8 +873,6 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
         rt2x00leds_register(rt2x00dev);
         rt2x00debug_register(rt2x00dev);
 
-        set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
-
         return 0;
 
 exit:
diff --git a/drivers/net/wireless/rt2x00/rt2x00link.c b/drivers/net/wireless/rt2x00/rt2x00link.c
index c64db0ba7f40..c708d0be9155 100644
--- a/drivers/net/wireless/rt2x00/rt2x00link.c
+++ b/drivers/net/wireless/rt2x00/rt2x00link.c
@@ -362,8 +362,9 @@ void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
 
         rt2x00link_reset_tuner(rt2x00dev, false);
 
-        ieee80211_queue_delayed_work(rt2x00dev->hw,
-                                     &link->work, LINK_TUNE_INTERVAL);
+        if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
+                ieee80211_queue_delayed_work(rt2x00dev->hw,
+                                             &link->work, LINK_TUNE_INTERVAL);
 }
 
 void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev)
@@ -469,8 +470,10 @@ static void rt2x00link_tuner(struct work_struct *work)
          * Increase tuner counter, and reschedule the next link tuner run.
          */
         link->count++;
-        ieee80211_queue_delayed_work(rt2x00dev->hw,
-                                     &link->work, LINK_TUNE_INTERVAL);
+
+        if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
+                ieee80211_queue_delayed_work(rt2x00dev->hw,
+                                             &link->work, LINK_TUNE_INTERVAL);
 }
 
 void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 501544882c2c..f02b48a90593 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -47,6 +47,8 @@ int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
             (requesttype == USB_VENDOR_REQUEST_IN) ?
             usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);
 
+        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
+                return -ENODEV;
 
         for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
                 status = usb_control_msg(usb_dev, pipe, request, requesttype,
@@ -60,8 +62,10 @@ int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
                  * -ENODEV: Device has disappeared, no point continuing.
                  * All other errors: Try again.
                  */
-                else if (status == -ENODEV)
+                else if (status == -ENODEV) {
+                        clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
                         break;
+                }
         }
 
         ERROR(rt2x00dev,
@@ -161,6 +165,9 @@ int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
 {
         unsigned int i;
 
+        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
+                return -ENODEV;
+
         for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
                 rt2x00usb_register_read_lock(rt2x00dev, offset, reg);
                 if (!rt2x00_get_field32(*reg, field))