[ 25/78] genirq: Adjust irq thread affinity on IRQ_SET_MASK_OK_NOCOPY return value

From: Greg KH
Date: Wed Apr 11 2012 - 20:06:15 EST


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

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

From: Jiang Liu <liuj97@xxxxxxxxx>

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@xxxxxxxxxx>
Cc: Jiang Liu <liuj97@xxxxxxxxx>
Cc: Keping Chen <chenkeping@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1333120296-13563-2-git-send-email-jiang.liu@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/irq/migration.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -43,12 +43,16 @@ void irq_move_masked_irq(struct irq_data
* 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);
}


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