From: Olaf Hering <olaf@xxxxxxxxx>
The callbacks in kvp, vss and fcopy code are called both from the main thread
as well as from interrupt context. If a state change is done by the main
thread it is not immediately seen by the interrupt. As a result the
state machine gets out of sync.
Force propagation of state changes via get/set helpers with a memory barrier.
Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/hyperv_vmbus.h | 14 ++++++++++++++
1 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 4b1eb6d..dee5798 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -780,4 +780,18 @@ enum hvutil_device_state {
HVUTIL_DEVICE_DYING, /* driver unload is in progress */
};
+static inline void hvutil_device_set_state(enum hvutil_device_state *p,
+ enum hvutil_device_state s)
+{
+ *p = s;
+ wmb();
+}
+
+static inline enum hvutil_device_state
+hvutil_device_get_state(enum hvutil_device_state *p)
+{
+ rmb();
+ return *p;
+}
+
#endif /* _HYPERV_VMBUS_H */
--
1.7.4.1
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