Patch "MIPS: BMIPS: Do not mask IPIs during suspend" has been added to the 3.18-stable tree

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

MIPS: BMIPS: Do not mask IPIs during suspend

to the 3.18-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:
mips-bmips-do-not-mask-ipis-during-suspend.patch
and it can be found in the queue-3.18 subdirectory.

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

From: Justin Chen <[email protected]>
Date: Wed, 27 Sep 2017 17:15:15 -0700
Subject: MIPS: BMIPS: Do not mask IPIs during suspend

From: Justin Chen <[email protected]>

commit 06a3f0c9f2725f5d7c63c4203839373c9bd00c28 upstream.

Commit a3e6c1eff548 ("MIPS: IRQ: Fix disable_irq on CPU IRQs") fixes an issue where disable_irq did not actually disable the irq. The bug caused our IPIs to not be disabled, which actually is the correct behavior.

With the addition of commit a3e6c1eff548 ("MIPS: IRQ: Fix disable_irq on CPU IRQs"), the IPIs were getting disabled going into suspend, thus schedule_ipi() was not being called. This caused deadlocks where schedulable task were not being scheduled and other cpus were waiting for them to do something.

Add the IRQF_NO_SUSPEND flag so an irq_disable will not be called on the IPIs during suspend.

Patchwork: https://patchwork.linux-mips.org/patch/17385/

---
 arch/mips/kernel/smp-bmips.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

@@ -159,11 +159,11 @@ static void bmips_prepare_cpus(unsigned
 		return;
 	}
 
-	if (request_irq(IPI0_IRQ, bmips_ipi_interrupt, IRQF_PERCPU,
-			"smp_ipi0", NULL))
+	if (request_irq(IPI0_IRQ, bmips_ipi_interrupt,
+			IRQF_PERCPU | IRQF_NO_SUSPEND, "smp_ipi0", NULL))
 		panic("Can't request IPI0 interrupt");
-	if (request_irq(IPI1_IRQ, bmips_ipi_interrupt, IRQF_PERCPU,
-			"smp_ipi1", NULL))
+	if (request_irq(IPI1_IRQ, bmips_ipi_interrupt,
+			IRQF_PERCPU | IRQF_NO_SUSPEND, "smp_ipi1", NULL))
 		panic("Can't request IPI1 interrupt");
 }
 

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

queue-3.18/mips-bmips-do-not-mask-ipis-during-suspend.patch