genirq: Adjust irq thread affinity on IRQ_SET_MASK_OK_NOCOPY return value

BugLink: http://bugs.launchpad.net/bugs/983326

commit f5cb92ac82d06cb583c1f66666314c5c0a4d7913 upstream.

irq_move_masked_irq() checks the return code of
chip->irq_set_affinity() only for 0, but IRQ_SET_MASK_OK_NOCOPY is
also a valid return code, which is there to avoid a redundant copy of
the cpumask. But in case of IRQ_SET_MASK_OK_NOCOPY we not only avoid
the redundant copy, we also fail to adjust the thread affinity of an
eventually threaded interrupt handler.

Handle IRQ_SET_MASK_OK (==0) and IRQ_SET_MASK_OK_NOCOPY(==1) return
values correctly by checking the valid return values seperately.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Keping Chen <chenkeping@huawei.com>
Link: http://lkml.kernel.org/r/1333120296-13563-2-git-send-email-jiang.liu@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 47420908fba..c3c89751b32 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -43,12 +43,16 @@ void irq_move_masked_irq(struct irq_data *idata)
          * masking the irqs.
          */
         if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
-                   < nr_cpu_ids))
-                if (!chip->irq_set_affinity(&desc->irq_data,
-                                            desc->pending_mask, false)) {
+                   < nr_cpu_ids)) {
+                int ret = chip->irq_set_affinity(&desc->irq_data,
+                                                 desc->pending_mask, false);
+                switch (ret) {
+                case IRQ_SET_MASK_OK:
                         cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
+                case IRQ_SET_MASK_OK_NOCOPY:
                         irq_set_thread_affinity(desc);
                 }
+        }
 
         cpumask_clear(desc->pending_mask);
 }