Re: [PATCH v2] irqchip/sifive-plic: Respect mask state when setting affinity

From: Chen Wang
Date: Thu Aug 21 2025 - 02:37:53 EST



On 8/11/2025 8:26 AM, Inochi Amaoto wrote:
The plic_set_affinity always call plic_irq_enable(), which clears up
the priority setting even the irq is only masked. This make the irq
unmasked unexpectly.

Replace the plic_irq_enable/disable() with plic_irq_toggle() to
avoid changing priority setting.

Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxx>
Reviewed-by: Nam Cao <namcao@xxxxxxxxxxxxx>
Tested-by: Nam Cao <namcao@xxxxxxxxxxxxx> # VisionFive 2

Reviewed-by: Chen Wang <unicorn_wang@xxxxxxxxxxx>

It is recommended to add the following email link about the relevant discussion in the commit message for quich reference when there is a revision or merge:

https://lore.kernel.org/lkml/20250722224513.22125-1-inochiama@xxxxxxxxx/

Tested-by: Chen Wang <unicorn_wang@xxxxxxxxxxx> # Pioneerbox

---
Change from v1:
1. apply Nam's tag
2. remove unnecessary off-topic change in plic_irq_disable()
---
drivers/irqchip/irq-sifive-plic.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index bf69a4802b71..866e38612b94 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -179,12 +179,14 @@ static int plic_set_affinity(struct irq_data *d,
if (cpu >= nr_cpu_ids)
return -EINVAL;

- plic_irq_disable(d);
+ /* Invalidate the original routing entry */
+ plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 0);

irq_data_update_effective_affinity(d, cpumask_of(cpu));

+ /* Setting the new routing entry if irq is enabled */
if (!irqd_irq_disabled(d))
- plic_irq_enable(d);
+ plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 1);

return IRQ_SET_MASK_OK_DONE;
}
--
2.50.1


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