On Tue, Oct 04, 2022 at 11:41:50AM +0200, Sebastian Andrzej Siewior wrote: > On 2022-10-03 13:08:49 [-0400], Eric Chanudet wrote: > > PREEMPT_RT forces qcom-ipcc's handler to be threaded with interrupts > > enabled, which triggers a warning in __handle_irq_event_percpu(): > > irq 173 handler irq_default_primary_handler+0x0/0x10 enabled interrupts > > WARNING: CPU: 0 PID: 77 at kernel/irq/handle.c:161 __handle_irq_event_percpu+0x4c4/0x4d0 > > > > Mark it IRQF_NO_THREAD to avoid running the handler in a threaded > > context with threadirqs or PREEMPT_RT enabled. > > The important bit of information is that this is a IRQ-multiplexer and > such it must not be threaded. Otherwise its child-interrupts would be > invoked from the thread handler which is not desired. > This is noticed by PREEMPT_RT but also on a non-PREEMPT_RT kernel where > `threadirqs' has been used. Thank you, I will send a v2 shortly updating the description with the above. > Side note: Using request_irq() has the side effect that this interrupt > pops-up in /proc/interrupts and the "child-interrupt", too. So you > account two interrupts while "one" on the HW side occurred. > Maybe irq_set_chained_handler_and_data() would be better use. I see. > Either way, this addresses the problem, -- Eric Chanudet
