Re: lost interrupts when running sabrelite images (v4.15+) in qemu

From: Troy Kisky
Date: Sat Mar 03 2018 - 14:08:09 EST


On 3/3/2018 8:32 AM, Guenter Roeck wrote:
> Hi,
>
> since v4.15, I get the following runtime warning when running sabrelite images
> in qemu.
>
> irq 65: nobody cared (try booting with the "irqpoll" option)
> ...
> handlers:
> [<26292474>] fec_pps_interrupt
> Disabling IRQ #65
> fec 2188000.ethernet (unnamed net_device) (uninitialized): MDIO read timeout
>
> Bisect points to commit 4ad1ceec05e491 ("net: fec: Let fec_ptp have its
> own interrupt routine"). Analysis shows that platform_irq_count()
> returns 2, which is reduced to 1 by fec_enet_get_irq_cnt().
> If I let fec_enet_get_irq_cnt() return 2, the problem is gone.
> Reverting commit 4ad1ceec05e491 also fixes the problem.
>
> Bisect log is attached.
>

Sounds like you found a bug with qemu. I just booted sabrelite over nfs fine.
My interrupts look like this.


64: 98767 0 0 0 GIC-0 150 Level 2188000.ethernet
65: 0 0 0 0 GIC-0 151 Level 2188000.ethernet
___________
Irq 65 is only for ptp interrrupts now. If qemu is signaling an tx/rx frame interrupt on 65,
then qemu is wrong. Of course, I've never used qemu so feel free to ignore me if I make no sense.


BR
Troy