Patch "x86/irq: Make irq activate operations symmetric" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

x86/irq: Make irq activate operations symmetric

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-irq-make-irq-activate-operations-symmetric.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Thomas Gleixner <[email protected]>
Date: Tue, 31 Jan 2017 19:03:21 +0100
Subject: x86/irq: Make irq activate operations symmetric

From: Thomas Gleixner <[email protected]>

commit aaaec6fc755447a1d056765b11b24d8ff2b81366 upstream.

The recent commit which prevents double activation of interrupts unearthed interesting code in x86. The code (ab)uses irq_domain_activate_irq() to reconfigure an already activated interrupt. That trips over the prevention code now.

Fix it by deactivating the interrupt before activating the new configuration.

---
 arch/x86/kernel/apic/io_apic.c |    2 ++
 arch/x86/kernel/hpet.c         |    1 +
 2 files changed, 3 insertions(+)

@@ -2117,6 +2117,7 @@ static inline void __init check_timer(vo
 			if (idx != -1 && irq_trigger(idx))
 				unmask_ioapic_irq(irq_get_chip_data(0));
 		}
+		irq_domain_deactivate_irq(irq_data);
 		irq_domain_activate_irq(irq_data);
 		if (timer_irq_works()) {
 			if (disable_timer_pin_1 > 0)

@@ -2138,6 +2139,7 @@ static inline void __init check_timer(vo
 		 * legacy devices should be connected to IO APIC #0
 		 */
 		replace_pin_at_irq_node(data, node, apic1, pin1, apic2, pin2);
+		irq_domain_deactivate_irq(irq_data);
 		irq_domain_activate_irq(irq_data);
 		legacy_pic->unmask(0);
 		if (timer_irq_works()) {

@@ -351,6 +351,7 @@ static int hpet_resume(struct clock_even
 	} else {
 		struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt);
 
+		irq_domain_deactivate_irq(irq_get_irq_data(hdev->irq));
 		irq_domain_activate_irq(irq_get_irq_data(hdev->irq));
 		disable_irq(hdev->irq);
 		irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/x86-irq-make-irq-activate-operations-symmetric.patch queue-4.4/perf-core-fix-perf_record_mmap2-prot-flags-for-anonymous-memory.patch