From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 23 Oct 2008 11:01:03 +0000 (+0100)
Subject: hpet cpuidle: Observe IRQ-safe locking protocol.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14054^2~42
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=13dbb4fd446a7f93e63120069480a5a3d416cf20;p=xen.git

hpet cpuidle: Observe IRQ-safe locking protocol.

Otherwise, may encounter deadlock.

Signed-off-by: Wei Gang <gang.wei@intel.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---

diff --git a/xen/arch/x86/hpet.c b/xen/arch/x86/hpet.c
index 5a660245b6..443d487f67 100644
--- a/xen/arch/x86/hpet.c
+++ b/xen/arch/x86/hpet.c
@@ -146,7 +146,7 @@ static void handle_hpet_broadcast(struct hpet_event_channel *ch)
     s_time_t now, next_event;
     int cpu;
 
-    spin_lock(&ch->lock);
+    spin_lock_irq(&ch->lock);
 
 again:
     ch->next_event = STIME_MAX;
@@ -171,7 +171,7 @@ again:
         if ( reprogram_hpet_evt_channel(ch, next_event, now, 0) )
             goto again;
     }
-    spin_unlock(&ch->lock);
+    spin_unlock_irq(&ch->lock);
 }
 
 void hpet_broadcast_init(void)
@@ -213,6 +213,7 @@ void hpet_broadcast_enter(void)
 {
     struct hpet_event_channel *ch = &hpet_event;
 
+    ASSERT(!local_irq_is_enabled());
     spin_lock(&ch->lock);
 
     disable_APIC_timer();