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authorDavid S. Miller <davem@davemloft.net>2013-04-01 13:36:50 -0400
committerDavid S. Miller <davem@davemloft.net>2013-04-01 13:36:50 -0400
commita210576cf891e9e6d2c238eabcf5c1286b1e7526 (patch)
tree0fa81a901cf628b25e6ee79057700cf39e59818a /drivers/xen/events.c
parent7d4c04fc170087119727119074e72445f2bb192b (diff)
parent3658f3604066d5500ebd73a04084f127dc779441 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: net/mac80211/sta_info.c net/wireless/core.h Two minor conflicts in wireless. Overlapping additions of extern declarations in net/wireless/core.h and a bug fix overlapping with the addition of a boolean parameter to __ieee80211_key_free(). Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/xen/events.c')
-rw-r--r--drivers/xen/events.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index d17aa41a904..aa85881d17b 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -403,11 +403,23 @@ static void unmask_evtchn(int port)
if (unlikely((cpu != cpu_from_evtchn(port))))
do_hypercall = 1;
- else
+ else {
+ /*
+ * Need to clear the mask before checking pending to
+ * avoid a race with an event becoming pending.
+ *
+ * EVTCHNOP_unmask will only trigger an upcall if the
+ * mask bit was set, so if a hypercall is needed
+ * remask the event.
+ */
+ sync_clear_bit(port, BM(&s->evtchn_mask[0]));
evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0]));
- if (unlikely(evtchn_pending && xen_hvm_domain()))
- do_hypercall = 1;
+ if (unlikely(evtchn_pending && xen_hvm_domain())) {
+ sync_set_bit(port, BM(&s->evtchn_mask[0]));
+ do_hypercall = 1;
+ }
+ }
/* Slow path (hypercall) if this is a non-local port or if this is
* an hvm domain and an event is pending (hvm domains don't have
@@ -418,8 +430,6 @@ static void unmask_evtchn(int port)
} else {
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
- sync_clear_bit(port, BM(&s->evtchn_mask[0]));
-
/*
* The following is basically the equivalent of
* 'hw_resend_irq'. Just like a real IO-APIC we 'lose