From d7f39c40ebb6986e7371510d1c20a4efee4a7f0d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 18 Dec 2020 18:03:46 +0000 Subject: [PATCH] irqchip/bcm2836: Fix IPI acknowledgement after conversion to handle_percpu_devid_irq It appears that despite its name, the bcm2836_arm_irqchip_ipi_eoi() callback is an acknowledgement, and not an EOI. This means that we lose IPIs that are made pending between the handling of the IPI and the write to LOCAL_MAILBOX0_CLR0. With the right timing, things fail nicely. This used to work with handle_percpu_devid_fasteoi_ipi(), which started by eoi-ing the interrupt. With the standard fasteoi flow, this doesn't work anymore. So let's use this callback for what it is, an ack. Your favourite RPi-2/3 is back up and running. Fixes: ffdad793d579 ("irqchip/bcm2836: Make IPIs use handle_percpu_devid_irq()") Cc: Valentin Schneider Reported-by: Guenter Roeck Tested-by: Guenter Roeck Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/c9fb4ab3-a5cb-648c-6de3-c6a871e60870@roeck-us.net --- drivers/irqchip/irq-bcm2836.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c index 5f5eb8877c41..25c9a9c06e41 100644 --- a/drivers/irqchip/irq-bcm2836.c +++ b/drivers/irqchip/irq-bcm2836.c @@ -167,7 +167,7 @@ static void bcm2836_arm_irqchip_handle_ipi(struct irq_desc *desc) chained_irq_exit(chip, desc); } -static void bcm2836_arm_irqchip_ipi_eoi(struct irq_data *d) +static void bcm2836_arm_irqchip_ipi_ack(struct irq_data *d) { int cpu = smp_processor_id(); @@ -195,7 +195,7 @@ static struct irq_chip bcm2836_arm_irqchip_ipi = { .name = "IPI", .irq_mask = bcm2836_arm_irqchip_dummy_op, .irq_unmask = bcm2836_arm_irqchip_dummy_op, - .irq_eoi = bcm2836_arm_irqchip_ipi_eoi, + .irq_ack = bcm2836_arm_irqchip_ipi_ack, .ipi_send_mask = bcm2836_arm_irqchip_ipi_send_mask, };