Re: [PATCH 3/5] irqchip/bcm2836: Make IPIs use handle_percpu_devid_irq()

From: Marc Zyngier
Date: Tue Dec 15 2020 - 05:20:27 EST


Hi Gunter,

On 2020-12-15 00:21, Guenter Roeck wrote:
On Mon, Nov 09, 2020 at 09:41:19AM +0000, Valentin Schneider wrote:
As done for the Arm GIC irqchips, move IPIs to handle_percpu_devid_irq() as
handle_percpu_devid_fasteoi_ipi() isn't actually required.

Signed-off-by: Valentin Schneider <valentin.schneider@xxxxxxx>

This patch results in boot failures (silent stall) for the qemu
raspi2 emulation. Unfortunately it can not be reverted because
handle_percpu_devid_fasteoi_ipi no longer exists in next-20201214,
so I don't know if it is the only problem.

This is odd. This works just fine for me on both the RPi2 and 3
emulation, running a full Debian userspace. Could this be caused
by the version of QEMU you are using? Here's what I have:

$ qemu-system-arm --version
QEMU emulator version 5.1.0 (Debian 1:5.1+dfsg-4+b1)

Could you try the following hack and let me know if that helps?

Thanks,

M.

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,
};
--
Jazz is not dead. It just smells funny...