MIPS: BMIPS: Do not mask IPIs during suspend

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.

Signed-off-by: Justin Chen <justinpopo6@gmail.com>
Fixes: a3e6c1eff548 ("MIPS: IRQ: Fix disabled_irq on CPU IRQs")
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17385/
[jhogan@kernel.org: checkpatch: wrap long lines and fix commit refs]
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index 87dcac2447c8df20a572139d5053624e91acf2ca..382d12eb88f0fa5743ea0bd724906bc61b241d58 100644 (file)
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -168,11 +168,11 @@ static void bmips_prepare_cpus(unsigned int max_cpus)
                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");
 }