Messages in this thread | | | Date | Tue, 27 Oct 2015 17:23:33 +0100 | Subject | Re: [PATCH] gpio: zynq: Implement irq_(request|release)_resources | From | Linus Walleij <> |
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On Tue, Oct 27, 2015 at 5:18 PM, Grygorii Strashko <grygorii.strashko@ti.com> wrote: > 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().
Do you mean that these functions contain calls to non-atomic functions?
I mainly reacted to this because it was pm_* calls, that you mentioned explicitly in your patch.
Yours, Linus Walleij
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