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Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when GPIOLIB is disabled

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On Mon, Feb 13, 2017 at 08:45:06AM +0100, Uwe Kleine-König wrote:
> Hello,
> 
> On Sun, Feb 12, 2017 at 05:15:01PM -0800, Dmitry Torokhov wrote:
> > On Sun, Feb 12, 2017 at 05:13:55PM -0800, Dmitry Torokhov wrote:
> > > Given the intent behind gpiod_get_optional() and friends it does not make
> > > sense to return -ENOSYS when GPIOLIB is disabled: the driver is expected to
> > > work just fine without gpio so let's behave as if gpio was not found.
> > > Otherwise we have to special-case -ENOSYS in drivers.
> > > 
> > > Note that there was objection that someone might forget to enable GPIOLIB
> > > when dealing with a platform that has device that actually specifies
> > > optional gpio and we'll break it. I find this unconvincing as that would
> > > have to be the *only GPIO* in the system, which is extremely unlikely.
> > > 
> > > Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> 
> I don't like this patch and so I wonder what I wrote that could be
> interpreted as suggesting this patch. For now I'd say only
> 
> 	Nacked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> 
> is justified.

Oh, it seems I really sent such a RFC patch some time ago. Still I think
it's wrong to do that and that we need something like a
lookup-only-GPIOLIB that implements:

	def gpio_get_optional(...):
		if a gpio is specified:
			return -ENOSYS
		else:
			return NULL

if you really want save some bytes and disable the full-fledged GPIOLIB.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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[PATCH v2] gpio: return NULL from gpiod_get_optional when GPIOLIB is  disabled Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-02-13 02:20 +0100
  Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-02-13 02:20 +0100
    Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Uwe Kleine-König          <u.kleine-koenig@pengutronix.de> - 2017-02-13 08:50 +0100
      Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Uwe Kleine-König          <u.kleine-koenig@pengutronix.de> - 2017-02-13 09:30 +0100
      Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-02-13 09:30 +0100
        Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Uwe Kleine-König          <u.kleine-koenig@pengutronix.de> - 2017-02-13 10:00 +0100
          Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-02-13 18:40 +0100
  Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when GPIOLIB  is disabled Linus Walleij <linus.walleij@linaro.org> - 2017-02-22 17:10 +0100
    Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2017-02-22 19:30 +0100
      Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Mark Brown <broonie@kernel.org> - 2017-02-22 20:00 +0100
    Re: [PATCH v2] gpio: return NULL from gpiod_get_optional when  GPIOLIB is disabled Mark Brown <broonie@kernel.org> - 2017-02-22 19:50 +0100

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