Messages in this thread Patch in this message | | | From | "K. Y. Srinivasan" <> | Subject | [PATCH 2/5] hv: add helpers to handle hv_util device state | Date | Tue, 15 Sep 2015 17:37:51 -0700 |
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From: Olaf Hering <olaf@aepfle.de>
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@aepfle.de> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> --- 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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