> -----Original Message----- > From: Arnd Bergmann [mailto:[email protected]] > Sent: Friday, February 12, 2021 10:45 PM > To: Song Bao Hua (Barry Song) <[email protected]> > Cc: Grygorii Strashko <[email protected]>; luojiaxing > <[email protected]>; Linus Walleij <[email protected]>; Andy > Shevchenko <[email protected]>; Andy Shevchenko > <[email protected]>; Santosh Shilimkar <[email protected]>; > Kevin Hilman <[email protected]>; open list:GPIO SUBSYSTEM > <[email protected]>, [email protected] > <[email protected]>; [email protected] > Subject: Re: [Linuxarm] Re: [PATCH for next v1 1/2] gpio: omap: Replace > raw_spin_lock_irqsave with raw_spin_lock in omap_gpio_irq_handler() > > On Fri, Feb 12, 2021 at 6:05 AM Song Bao Hua (Barry Song) > <[email protected]> wrote: > > > -----Original Message----- > > > > > > > Note. there is also generic_handle_irq() call inside. > > > > So generic_handle_irq() is not safe to run in thread thus requires > > an interrupt-disabled environment to run? If so, I'd rather this > > irqsave moved into generic_handle_irq() rather than asking everyone > > calling it to do irqsave. > > In a preempt-rt kernel, interrupts are run in task context, so they clearly > should not be called with interrupts disabled, that would defeat the > purpose of making them preemptible.
Yes. Sounds sensible. Irqsave in generic_handle_irq() will defeat the purpose of RT. > > generic_handle_irq() does need to run with in_irq()==true though, > but this should be set by the caller of the gpiochip's handler, and > it is not set by raw_spin_lock_irqsave(). > So sounds like this issue of in_irq()=true is still irrelevant with this patch. I guess this should have been set by the caller of the gpiochip's handler somewhere, otherwise, gpiochip's irq handler won't be able to be threaded. Has it been set somewhere? > Arnd Thanks Barry
