linux-kernel - Re: [PATCH v4 2/3] Input: edt-ft5x06 - Set wake/reset values on resume/suspend

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Message-ID: <20180726005212.GE80336@dtor-ws>
Date:   Wed, 25 Jul 2018 17:52:12 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Mylène Josserand <mylene.josserand@...tlin.com>
Cc:     robh+dt@...nel.org, mark.rutland@....com,
        maxime.ripard@...tlin.com, wens@...e.org,
        linux-input@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        thomas.petazzoni@...tlin.com
Subject: Re: [PATCH v4 2/3] Input: edt-ft5x06 - Set wake/reset values on
 resume/suspend

Hi Mylène,

On Wed, Jul 25, 2018 at 09:34:09AM +0200, Mylène Josserand wrote:
> On resume and suspend, set the value of wake and reset gpios
> to be sure that we are in a know state after suspending/resuming.
> 
> Signed-off-by: Mylène Josserand <mylene.josserand@...tlin.com>
> ---
>  drivers/input/touchscreen/edt-ft5x06.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> index dcde719094f7..dad2f1f8bf89 100644
> --- a/drivers/input/touchscreen/edt-ft5x06.c
> +++ b/drivers/input/touchscreen/edt-ft5x06.c
> @@ -1158,6 +1158,12 @@ static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
>  	else
>  		regulator_disable(tsdata->vcc);
>  
> +	if (tsdata->wake_gpio)
> +		gpiod_set_value(tsdata->wake_gpio, 0);
> +
> +	if (tsdata->reset_gpio)
> +		gpiod_set_value(tsdata->reset_gpio, 1);

Ondřej mentioned in previous review that if you power off the controller
it will not be able to wake up the system, and you had to move call to
regulator_disable() into "else" branch of check whether the controller
is a wakeup device. Guess what happens if you unconditionally put the
device into reset state?

Thanks.

-- 
Dmitry