Re: [PATCH] gpio: mpc8xxx: Don't overwrite default irq_set_type callback

[Michael Walle]

> The per-SoC devtype structures can contain their own callbacks that
> overwrite mpc8xxx_gpio_devtype_default.
>
> The clear intention is that mpc8xxx_irq_set_type is used in case the 
> SoC
> does not specify a more specific callback. But what happens is that if
> the SoC doesn't specify one, its .irq_set_type is de-facto NULL, and
> this overwrites mpc8xxx_irq_set_type to a no-op. This means that the
> following SoCs are affected:
>
> - fsl,mpc8572-gpio
> - fsl,ls1028a-gpio
> - fsl,ls1088a-gpio
>
> On these boards, the irq_set_type does exactly nothing, and the GPIO
> controller keeps its GPICR register in the hardware-default state. On
> the LS1028A, that is ACTIVE_BOTH, which means 2 interrupts are raised
> even if the IRQ client requests LEVEL_HIGH. Another implication is that
> the IRQs are not checked (e.g. level-triggered interrupts are not
> rejected, although they are not supported).
>
> Fixes: 82e39b0d8566 ("gpio: mpc8xxx: handle differences between 
> incarnations at a single place")
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>

Tested-by: Michael Walle <michael@xxxxxxxx>