rt2x00: Implement watchdog monitoring

Implement watchdog monitoring for USB devices (PCI support can
be added later). This will determine if URBs being uploaded to
the hardware are actually returning. Both rt2500usb and rt2800usb
have shown that URBs being uploaded can remain hanging without
being released by the hardware.
By using this watchdog, a queue can be reset when this occurs.
For rt2800usb it has been tested that the connection is preserved
even though this interruption.

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

1 files changed, 23 insertions, 3 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00lib.h b/drivers/net/wireless/rt2x00/rt2x00lib.h
index ed27de1de57b..dc5c6574aaf4 100644
--- a/drivers/net/wireless/rt2x00/rt2x00lib.h
+++ b/drivers/net/wireless/rt2x00/rt2x00lib.h
@@ -30,6 +30,7 @@
 /*
  * Interval defines
  */
+#define WATCHDOG_INTERVAL	round_jiffies_relative(HZ)
 #define LINK_TUNE_INTERVAL	round_jiffies_relative(HZ)
 
 /*
@@ -257,11 +258,30 @@ void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev);
 void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna);
 
 /**
- * rt2x00link_register - Initialize link tuning functionality
+ * rt2x00link_start_watchdog - Start periodic watchdog monitoring
  * @rt2x00dev: Pointer to &struct rt2x00_dev.
  *
- * Initialize work structure and all link tuning related
- * parameters. This will not start the link tuning process itself.
+ * This start the watchdog periodic work, this work will
+ *be executed periodically until &rt2x00link_stop_watchdog has
+ * been called.
+ */
+void rt2x00link_start_watchdog(struct rt2x00_dev *rt2x00dev);
+
+/**
+ * rt2x00link_stop_watchdog - Stop periodic watchdog monitoring
+ * @rt2x00dev: Pointer to &struct rt2x00_dev.
+ *
+ * After this function completed the watchdog monitoring will not
+ * be running until &rt2x00link_start_watchdog is called.
+ */
+void rt2x00link_stop_watchdog(struct rt2x00_dev *rt2x00dev);
+
+/**
+ * rt2x00link_register - Initialize link tuning & watchdog functionality
+ * @rt2x00dev: Pointer to &struct rt2x00_dev.
+ *
+ * Initialize work structure and all link tuning and watchdog related
+ * parameters. This will not start the periodic work itself.
  */
 void rt2x00link_register(struct rt2x00_dev *rt2x00dev);