atl1c: Fix work event interrupt/task races

The mechanism used to initiate work events from the interrupt
handler has a classic read/modify/write race between the interrupt
handler that sets the condition, and the worker task that reads and
clears the condition. Close these races by using atomic
bit fields.

Cc: stable@kernel.org
Cc: Jie Yang <jie.yang@atheros.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/atl1c/atl1c.h b/drivers/net/atl1c/atl1c.h
index 7cb375e..925929d 100644
--- a/drivers/net/atl1c/atl1c.h
+++ b/drivers/net/atl1c/atl1c.h
@@ -566,9 +566,9 @@
 #define __AT_TESTING        0x0001
 #define __AT_RESETTING      0x0002
 #define __AT_DOWN           0x0003
-	u8 work_event;
-#define ATL1C_WORK_EVENT_RESET 		0x01
-#define ATL1C_WORK_EVENT_LINK_CHANGE	0x02
+	unsigned long work_event;
+#define	ATL1C_WORK_EVENT_RESET		0
+#define	ATL1C_WORK_EVENT_LINK_CHANGE	1
 	u32 msg_enable;
 
 	bool have_msi;