Messages in this thread | | | Subject | Re: [PATCH] gpio: zynq: Implement irq_(request|release)_resources | From | Grygorii Strashko <> | Date | Tue, 27 Oct 2015 18:18:54 +0200 |
| |
On 10/27/2015 05:53 PM, Linus Walleij wrote: > On Fri, Oct 23, 2015 at 3:36 PM, Soren Brinkmann > <soren.brinkmann@xilinx.com> wrote: > >> The driver uses runtime PM to leverage low power techniques. For >> use-cases using GPIO as interrupt the device needs to be in an >> appropriate state. >> >> Reported-by: John Linn <linnj@xilinx.com> >> Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> >> Tested-by: John Linn <linnj@xilinx.com> > > As pointed out by Grygorii in > commit aca82d1cbb49af34b69ecd4571a0fe48ad9247c1: > > The PM runtime API can't be used in atomic contex on -RT even if > it's configured as irqsafe. As result, below error report can > be seen when PM runtime API called from IRQ chip's callbacks > irq_startup/irq_shutdown/irq_set_type, because they are > protected by RAW spinlock: > (...) > The IRQ chip interface defines only two callbacks which are executed in > non-atomic contex - irq_bus_lock/irq_bus_sync_unlock, so lets move > PM runtime calls there. > > I.e. these calls are atomic context and it's just luck that it works > and this is fragile. > > Can you please check if you can move it to > irq_bus_lock()/irq_sync_unlock() > like Grygorii does? >
This patch rises the question not only about PM runtime, but also about gpiochip_irq_reqres()/gpiochip_irq_relres().
-- regards, -grygorii
| |