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

From: Mika Westerberg
Date: Tue Nov 08 2016 - 04:17:51 EST


On Mon, Nov 07, 2016 at 08:29:03PM +0100, Thomas Gleixner wrote:
> Subject: genirq: Use irq type from irqdata instead of irqdesc
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Date: Mon, 07 Nov 2016 19:57:00 +0100
>
> The type flags in the irq descriptor are there for historical reasons and
> only updated via irq_modify_status() or irq_set_type(). Both functions also
> update the type flags in irqdata. __setup_irq() is the only left over user
> of the type flags in the irq descriptor.
>
> If __setup_irq() is called with empty irq type flags, then the type flags
> are retrieved from irqdata. If an interrupt is shared, then the type flags
> are compared with the type flags stored in the irq descriptor.
>
> On x86 the ioapic does not have a irq_set_type() callback because the type
> is defined in the BIOS tables and cannot be changed. The type is stored in
> irqdata at setup time without updating the type data in the irq
> descriptor. As a result the comparison described above fails.
>
> There is no point in updating the irq descriptor flags because the only
> relevant storage is irqdata. Use the type flags from irqdata for both
> retrieval and comparison in __setup_irq() instead.
>
> Aside of that the print out in case of non matching type flags has the old
> and new type flags arguments flipped. Fix that as well.
>
> For correctness sake the flags stored in the irq descriptor should be
> removed, but this is beyond the scope of this bugfix and will be done in a
> later patch.
>
> Fixes: 4b357daed698 ("genirq: Look-up trigger type if not specified by caller")
> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

This fixes it, thanks a lot!

Tested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>