Re: BUG? genirq: irq 14 uses trigger mode 8; requested 0

Jon Hunter
2016-11-01T14:24:52Z

Hi Mika,

On 01/11/16 13:02, Mika Westerberg wrote:
> Hi,
>
> I started seeing following messages on Intel Broxton when the
> pinctrl/GPIO driver [1] loads:
>
> [ 0.645786] genirq: irq 14 uses trigger mode 8; requested 0
>
> The driver shares interrupt with other GPIO "communities" or banks so it
> uses request_irq() instead of irq_set_chained_handler_and_data(). The
> driver does not specify IRQ flags as those come from ACPI resources.
>
> This started happen after commit 4b357daed698 ("genirq: Look-up trigger
> type if not specified by caller").
>
> I think this is what happens:
>
> 1. ACPI platform sets up the interrupt according what is in the _CRS
> of the GPIO device. This ends up setting trigger type for irq_data of
> the irq.
>
> 2. First GPIO device is found and the driver calls request_irq() which
> calls __setup_irq() where shared == 0.
>
> 3. Since new->flags is read back from irq_data we call __irq_set_trigger()
> passing the flags.
>
> 4. The parent IRQ chip, IO-APIC, does not have ->irq_set_type callback
> so __irq_set_trigger() never calls irq_settings_set_trigger_mask() for
> the desciptor.
>
> 5. The second GPIO device is found and this time shared == 1 so we
> end up comparing nmsk with omsk where nmsk was read from irq_data
> and omsk is read using irq_settings_get_trigger_mask().
>
> 6. Because we never called irq_settings_set_trigger_mask() for the
> descriptor, omsk is 0 and we print out a warning:
>
> [ 0.645786] genirq: irq 14 uses trigger mode 8; requested 0
>
> If I revert commit 4b357daed698 the warning goes away.
>
> Do you have any ideas how to get rid of the warning properly?

May be I am misunderstanding something here, but if the parent does not
have a ->irq_set_type callback, then it would seem that the type for the
interrupt should be not specified/set in the ACPI _CRS for the GPIO
device, right?

Thanks for the detailed description.

Cheers
Jon

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