Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()

Message header is modified by the hypervisor and we read it in a loop,
we need to prevent compilers from optimizing accesses. There are no such
optimizations at this moment, this is just a future proof.

Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vitaly Kuznetsov 2016-02-26 15:13:18 -08:00 committed by Greg Kroah-Hartman
parent 0f70b66975
commit d452ab7b4c

View file

@ -605,7 +605,7 @@ static void vmbus_wait_for_unload(void)
bool unloaded = false;
while (1) {
if (msg->header.message_type == HVMSG_NONE) {
if (READ_ONCE(msg->header.message_type) == HVMSG_NONE) {
mdelay(10);
continue;
}