[Linux-stm32] STM32MP151A sysfs

[Alexandre TORGUE]

On 6/16/22 17:19, Alexandre TORGUE wrote:
> Hi Kegl
> 
> On 6/15/22 07:41, Kegl Rohit wrote:
>> Hello!
>>
>> I could notice following issue with kernel version 5.10.61:
>> Exporting GPIO PB12 and PD12 via sysfs triggers a kernel ERROR.
>> After the error happend the gpio still got exported and seem to function.
>>
>> Both Pins are unclaimed:
>> grep -e PB12 -e PD12
>> /sys/kernel/debug/pinctrl/soc\:pin-controller at 50002000/pinmux-pins
>> pin 28 (PB12): UNCLAIMED
>> pin 60 (PD12): UNCLAIMED
>>
>> root at dev:/sys/class/gpio# echo 60 > export
>> root at dev:/sys/class/gpio# echo 28 > export
>> [   30.467370] stm32mp157-pinctrl soc:pin-controller at 50002000: irq
>> line 12 already requested.
>>
>> The order does not matter:
>> root at dev:/sys/class/gpio# echo 60 > export
>> root at dev:/sys/class/gpio# echo 28 > export
>> [   20.768493] stm32mp157-pinctrl soc:pin-controller at 50002000: irq
>> line 12 already requested.
>>
>> This is the dev_err code part:
>> https://github.com/STMicroelectronics/linux/commit/8eb2dfee9fb1277f635ce369ef8669df0ec421bc#diff-549d83503a258940ffa6617dbbf4859d463fcac94f376b45b1744d243ffe9b16R381 
>>
>>
>> Seems that gpio sysfs requests an IRQ every time and there is some
>> shared IRQ limitation which is not implemented / handled yet.
>>
>> Can someone reproduce this? Maybe it is only a usage / kernel /
>> devicetree setup error by me...
>> Or is this a STM32MP1 limitation? gpio sysfs bug with STM32MP1? ...
>>
> 
> I just do the test on my DK2 board. I'm not able to reproduce (even if I 
> add a gio-keys using the EXTI line 12).
> 
> Which STM32MP151 do you use ?

Note also that this interface seems to be deprecated since v4.8. Some 
tips to move on the new interface in the following link:

https://www.thegoodpenguin.co.uk/blog/stop-using-sys-class-gpio-its-deprecated/


> 
> regards
> Alex
> 
> 
> 
>>
>> Thanks in advance.
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