Re: iio: dht11 broken

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Mon, Dec 1, 2014 at 11:59 AM, Richard Weinberger <richard@xxxxxx> wrote:
> Am 01.12.2014 um 11:49 schrieb Harald Geyer:

>> Any input from gpiolib people about what the proper fix would be in
>> their opinion, of course is appreciated. I don't think the dht11 driver
>> is doing anything unreasonable per se, so maybe they can clarify how
>> the API is intended to be used?
>
> Your driver sets up a GPIO as IRQ and then you switch the mode to output
> to enable the DHT sensor.
> This is not an API issue, it is an design issue.
> I'm not a hardware expert but AFAIK setting an IRQ pin into output mode can
> lead to undefined behavior.

Well that check is there exactly to prevent madness like this.

IRQs on pins set to output *does* *not* *make* *sense*.

Remove the IRQ before setting the pin to output and vice
versa and everyone will be happier.

Yours,
Linus Walleij
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