[PATCH v7 4/5] irqchip/loongarch-avec.c:return IRQ_SET_MASK_OK_DONE when keep affinity

[Tianyang Zhang]

When it is detected in avecintc_set_affinity that the current affinity
remains valid, the return value is modified to IRQ_SET_MASK_OK_DONE.

After the introduction of redirect-domain, for each interrupt source,
avecintc-domain only provides the CPU/interrupt vector, while redirect-domain
provides other operations to synchronize interrupt affinity information
among multiple cores. The original intention is to notify the cascaded
redirect_set_affinity that multi-core synchronization is not required.

However, this introduces some compatibility issues, such as the new return
value causing msi_domain_set_affinity to no longer perform irq_chip_write_msi_msg.
  1) When redirect exist in the system, the msi msg_address and msg_data no
longer changes after the allocation phase, so it does not actually require updating
the MSI message info.
  2) When only avecintc exists in the system, the irq_domain_activate_irq
interface will be responsible for the initial configuration of the MSI message,
which is unconditional. After that, if unnecessary, no modification to the MSI
message is alse correctly.

Signed-off-by: Tianyang Zhang <zhangtianyang@xxxxxxxxxxx>
---
 drivers/irqchip/irq-loongarch-avec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-loongarch-avec.c b/drivers/irqchip/irq-loongarch-avec.c
index 514ad8dedc46..ac8c423e411e 100644
--- a/drivers/irqchip/irq-loongarch-avec.c
+++ b/drivers/irqchip/irq-loongarch-avec.c
@@ -99,7 +99,7 @@ static int avecintc_set_affinity(struct irq_data *data, const struct cpumask *de
 			return -EBUSY;
 
 		if (cpu_online(adata->cpu) && cpumask_test_cpu(adata->cpu, dest))
-			return 0;
+			return IRQ_SET_MASK_OK_DONE;
 
 		cpumask_and(&intersect_mask, dest, cpu_online_mask);
 
-- 
2.41.0