[Letux-kernel] Bug in i2c_device_probe

H. Nikolaus Schaller hns at goldelico.com
Mon Jun 11 10:51:54 CEST 2018


Hi Tony,

> Am 11.06.2018 um 09:54 schrieb Tony Lindgren <tony at atomide.com>:
> 
> * H. Nikolaus Schaller <hns at goldelico.com> [180611 07:20]:
>> Hi Tony,
>> 
>>> Am 11.06.2018 um 09:07 schrieb Tony Lindgren <tony at atomide.com>:
>>> 
>>> * H. Nikolaus Schaller <hns at goldelico.com> [180610 08:33]:
>>>> Hi Tony,
>>>> I've observed this message on the Pyra with letux-4.17.0-lpae kernel:
>>>> 
>>>> [    1.806477] platform 48070000.i2c: Retrying from deferred list
>>>> [    1.813802] ------------[ cut here ]------------
>>>> [    1.818666] WARNING: CPU: 1 PID: 778 at drivers/irqchip/irq-gic.c:1016 gic_irq_domain_translate+0x78/0x100
>>> 
>>> Yes that needs to be fixed for all omap5 for the IRQ_TYPE_NONE
>>> users. We just need to set the proper EDGE/LEVEL and the
>>> direction for them in the omap5.dtsi file.
>>> 
>>>> The code has a comment:
>>>> 
>>>> 1015		/* Make it clear that broken DTs are... broken */
>>>> 1016		WARN_ON(*type == IRQ_TYPE_NONE);
>>>> 
>>>> This would mean that something in the core DT is broken as we import the omap5-common.dtsi.
>>>> 
>>>> I have researched a little:
>>> ...
>>>> Should this be #interrupt-cells = <2>?
>>> 
>>> No we just need to stop using IRQ_TYPE_NONE :)
>> 
>> The omap5.dtsi seems to be clean, but
>> 
>> fgrep -R 'interrupts = <GIC' arch/arm/boot/dts/omap5*.dts*
>> 
>> reports (amongst good cases)
>> 
>> arch/arm/boot/dts/omap5-board-common.dtsi:		interrupts = <GIC_SPI 7 IRQ_TYPE_NONE>; /* IRQ_SYS_1N */
>> arch/arm/boot/dts/omap5-board-common.dtsi:		interrupts = <GIC_SPI 119 IRQ_TYPE_NONE>; /* IRQ_SYS_2N cascaded to gic */
>> arch/arm/boot/dts/omap5-cm-t54.dts:		interrupts = <GIC_SPI 7 IRQ_TYPE_NONE>; /* IRQ_SYS_1N */
>> 
>> I.e. Palmas and twl6040.
>> 
>> So what would be the right edges/levels? Also IRQ_TYPE_LEVEL_HIGH?
> 
> Yes I think that is correct. Might be worth checking the PMIC docs
> and also see the comments in the following patch in Linux next:
> 
> 21135b6ec700 ("Revert "ARM: dts: am437x-sk-evm: Correct tps65218 irq type"")

Strangely it doesn't seem to make a difference if I specify
IRQ_TYPE_LEVEL_HIGH, IRQ_TYPE_LEVEL_LOW or IRQ_TYPE_LEVEL_NONE
in omap5-board-common.dtsi

So it is unfortunately not a low-hanging fruit to fix this issue...

@Marek: this is probably something you could start to look into
as soon as you have your Pyra prototype.

BR,
Nikolaus



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