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* BUG? genirq: irq 14 uses trigger mode 8; requested 0
@ 2016-11-01 13:02 Mika Westerberg
  2016-11-01 14:24 ` Jon Hunter
  0 siblings, 1 reply; 12+ messages in thread
From: Mika Westerberg @ 2016-11-01 13:02 UTC (permalink / raw)
  To: Jon Hunter; +Cc: Marc Zyngier, Thomas Gleixner, linux-kernel

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?

Thanks in advance.

[1] drivers/pinctrl/intel/pinctrl-intel.c

^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2016-11-08 14:22 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-11-01 13:02 BUG? genirq: irq 14 uses trigger mode 8; requested 0 Mika Westerberg
2016-11-01 14:24 ` Jon Hunter
2016-11-01 14:44   ` Mika Westerberg
2016-11-07 11:49     ` Mika Westerberg
2016-11-07 13:32       ` Jon Hunter
2016-11-07 14:40         ` Marc Zyngier
2016-11-07 14:59           ` Mika Westerberg
2016-11-07 15:50             ` Jon Hunter
2016-11-07 16:00               ` Thomas Gleixner
2016-11-07 19:29                 ` Thomas Gleixner
2016-11-08  9:17                   ` Mika Westerberg
2016-11-08 14:22                   ` [tip:irq/urgent] genirq: Use irq type from irqdata instead of irqdesc tip-bot for Thomas Gleixner

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