> -----Original Message----- > From: Arnd Bergmann [mailto:[email protected]] > Sent: Saturday, February 13, 2021 9:23 AM > To: Grygorii Strashko <[email protected]> > Cc: Song Bao Hua (Barry Song) <[email protected]>; Andy Shevchenko > <[email protected]>; luojiaxing <[email protected]>; Linus > Walleij <[email protected]>; Santosh Shilimkar <[email protected]>; > Kevin Hilman <[email protected]>; open list:GPIO SUBSYSTEM > <[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 12:53 PM Grygorii Strashko > <[email protected]> wrote: > > > > The worst RT case I can imagine is when gpio API is still called from hard > IRQ context by some > > other device driver - some toggling for example. > > Note. RT or "threadirqs" does not mean gpiochip become sleepable. > > > > In this case: > > threaded handler > > raw_spin_lock > > IRQ from other device > > hard_irq handler > > gpiod_x() > > raw_spin_lock_irqsave() -- oops > > > > Good point, I had missed the fact that drivers can call gpio functions from > hardirq context when I replied earlier, gpio is clearly special here.
Yes. Gpio provides APIs, thus, other drivers can go directly into the territory of gpio driver. Another one which is even more special might be m68k, which I cc-ed you yesterday: https://lore.kernel.org/lkml/[email protected]/ > > Arnd Thanks Barry
