On Sat, 29 Dec 2018 00:02:57 +0000,
Stefan Wahren <stefan.wah...@i2se.com> wrote:
Hi Stephan,
>
> Hi,
> while booting my Raspberry Pi 3 B+ with Linux 4.20 (arm64/defconfig)
> i'm getting the following warning:
>
> [ 11.005738] irq 79 handler irq_default_primary_handler+0x0/0x8 enabled
> interrupts
[...]
> This seems to come from the lan78xx driver, because i don't get this
> warning on the RPI 3B (smsc95xx).
>
> What's the approach to fix this issue? Is it just simply replace
> spin_lock_irq() with spin_lock_irqsave() at the right places?
No, this is more pathological than that. The USB framework seems to be
using threaded interrupts, which implies that interrupts are
re-enabled as soon as it has run.
In turn, this driver is using handle_simple_irq() as its flow, which
definitely expect interrupts to be disabled.
I have no insight in how this driver works, but I'm happy to help if
someone explains the interrupt flow of this thing.
M.
--
Jazz is not dead, it just smell funny.
