[ 12/28] x86: hpet: Fix masking of MSI interrupts

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Beulich <redacted>

commit 6acf5a8c931da9d26c8dd77d784daaf07fa2bff0 upstream.

HPET_TN_FSB is not a proper mask bit; it merely toggles between MSI and
legacy interrupt delivery. The proper mask bit is HPET_TN_ENABLE, so
use both bits when (un)masking the interrupt.

Signed-off-by: Jan Beulich <redacted>
Link: http://lkml.kernel.org/r/5093E09002000078000A60E6@nat28.tlf.novell.com
Signed-off-by: Thomas Gleixner <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/hpet.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c

@@ -431,7 +431,7 @@ void hpet_msi_unmask(struct irq_data *da
 
 	/* unmask it */
 	cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
-	cfg |= HPET_TN_FSB;
+	cfg |= HPET_TN_ENABLE | HPET_TN_FSB;
 	hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
 }
 

@@ -442,7 +442,7 @@ void hpet_msi_mask(struct irq_data *data
 
 	/* mask it */
 	cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
-	cfg &= ~HPET_TN_FSB;
+	cfg &= ~(HPET_TN_ENABLE | HPET_TN_FSB);
 	hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
 }