[Intel-wired-lan] [PATCH v3 10/14] mailbox: Use irq_update_affinity_hint

Nitesh Narayan Lal nitesh at redhat.com
Tue Jul 13 21:14:58 UTC 2021

The driver uses irq_set_affinity_hint() to:

- Set the affinity_hint which is consumed by the userspace for
  distributing the interrupts

- Enforce affinity

As per commit 6ac17fe8c14a ("mailbox: bcm-flexrm-mailbox: Set IRQ affinity
hint for FlexRM ring IRQs") the latter is done to ensure that the FlexRM
ring interrupts are evenly spread across all available CPUs. However, since
commit a0c9259dc4e1 ("irq/matrix: Spread interrupts on allocation") the
spreading of interrupts is dynamically performed at the time of allocation.
Hence, there is no need for the drivers to enforce their own affinity for
the spreading of interrupts.

Also, irq_set_affinity_hint() applying the provided cpumask as an affinity
for the interrupt is an undocumented side effect. To remove this side
effect irq_set_affinity_hint() has been marked as deprecated and new
interfaces have been introduced. Hence, replace the irq_set_affinity_hint()
with the new interface irq_update_affinity_hint() that only sets the
affinity_hint pointer.

Signed-off-by: Nitesh Narayan Lal <nitesh at redhat.com>
 drivers/mailbox/bcm-flexrm-mailbox.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mailbox/bcm-flexrm-mailbox.c b/drivers/mailbox/bcm-flexrm-mailbox.c
index 78073ad1f2f1..16982c13d323 100644
--- a/drivers/mailbox/bcm-flexrm-mailbox.c
+++ b/drivers/mailbox/bcm-flexrm-mailbox.c
@@ -1298,7 +1298,7 @@ static int flexrm_startup(struct mbox_chan *chan)
 	val = (num_online_cpus() < val) ? val / num_online_cpus() : 1;
 	cpumask_set_cpu((ring->num / val) % num_online_cpus(),
-	ret = irq_set_affinity_hint(ring->irq, &ring->irq_aff_hint);
+	ret = irq_update_affinity_hint(ring->irq, &ring->irq_aff_hint);
 	if (ret) {
 			"failed to set IRQ affinity hint for ring%d\n",
@@ -1425,7 +1425,7 @@ static void flexrm_shutdown(struct mbox_chan *chan)
 	/* Release IRQ */
 	if (ring->irq_requested) {
-		irq_set_affinity_hint(ring->irq, NULL);
+		irq_update_affinity_hint(ring->irq, NULL);
 		free_irq(ring->irq, ring);
 		ring->irq_requested = false;

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