linux-kernel - Re: [PATCH v2 1/1] pwm: pca9685: fix gpio-only operation.

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Message-ID: <CAGngYiXy+k0wwu23hoLB0rvB8j9P7hvAvoMeN_UA5A__AHD=dw@mail.gmail.com>
Date:   Wed, 12 Apr 2017 08:09:00 -0400
From:   Sven Van Asbroeck <thesven73@...il.com>
To:     Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        linux-pwm@...r.kernel.org, linux-kernel@...r.kernel.org,
        clemens.gruber@...ruber.com, andriy.shevchenko@...ux.intel.com,
        Sven Van Asbroeck <TheSven73@...glemail.com>
Subject: Re: [PATCH v2 1/1] pwm: pca9685: fix gpio-only operation.

On Wed, Apr 12, 2017 at 4:53 AM, Mika Westerberg
<mika.westerberg@...ux.intel.com> wrote:
> Looks like going to the right direction.

Thanks, I appreciate your comments !

>> +static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
> Why did you move the function here?

Because I added code that disables the output when the user releases
(unexports) the pwm or gpio.

If the output is not disabled on release (unexport):
- the output will remain in its previous state (possibly ON)
- when the last output is unexported, SLEEP is set, and all outputs
   are disabled at the same time
- this is counter-intuitive behaviour.

Expect a v3 patch soon which addresses your feedback.