irqchip/loongson-eiointc: Skip handling if there is no pending interrupt

eiointc_irq_dispatch() iterates over the pending bit registers of the
interrupt controller and evaluates the result even if there is no interrupt
pending in a particular 64bit chunk.

Skip handling and especially the pointless write back for clearing the
non-pending bits if a chunk is empty.

[ tglx: Massaged changelog ]

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/r/20240130082722.2912576-3-maobibo@loongson.cn
This commit is contained in:
Bibo Mao 2024-01-30 16:27:21 +08:00 committed by Thomas Gleixner
parent aafd753555
commit 3eece72ded

View File

@ -198,6 +198,12 @@ static void eiointc_irq_dispatch(struct irq_desc *desc)
for (i = 0; i < eiointc_priv[0]->vec_count / VEC_COUNT_PER_REG; i++) {
pending = iocsr_read64(EIOINTC_REG_ISR + (i << 3));
/* Skip handling if pending bitmap is zero */
if (!pending)
continue;
/* Clear the IRQs */
iocsr_write64(pending, EIOINTC_REG_ISR + (i << 3));
while (pending) {
int bit = __ffs(pending);