Re: [PATCH net v2] net: smc91x: Fix build without gpiolib

[David Miller <davem@davemloft.net>]

From: Tony Lindgren <tony@atomide.com>
Date: Fri, 12 Dec 2014 08:11:00 -0800

> * Tobias Klauser <tklauser@distanz.ch> [141212 08:09]:
>> If GPIOLIB=n the following build errors occur:
>> 
>> drivers/net/ethernet/smsc/smc91x.c: In function 'try_toggle_control_gpio':
>> drivers/net/ethernet/smsc/smc91x.c:2204:2: error: implicit declaration of function 'devm_gpiod_get_index' [-Werror=implicit-function-declaration]
>> drivers/net/ethernet/smsc/smc91x.c:2204:7: warning: assignment makes pointer from integer without a cast [enabled by default]
>> drivers/net/ethernet/smsc/smc91x.c:2213:2: error: implicit declaration of function 'gpiod_direction_output' [-Werror=implicit-function-declaration]
>> drivers/net/ethernet/smsc/smc91x.c:2216:3: error: implicit declaration of function 'devm_gpiod_put' [-Werror=implicit-function-declaration]
>> drivers/net/ethernet/smsc/smc91x.c:2222:2: error: implicit declaration of function 'gpiod_set_value_cansleep' [-Werror=implicit-function-declaration]
>> 
>> Since the toggling of the GPIOs is an optional feature, define
>> try_toggle_control_gpio only if GPIOLIB is enabled.
> 
> Oops sorry about that, I guess my systems have it all selected so
> randconfig builds did not expose it.
> 
> Would it make sense to add the missing gpio stub into
> include/linux/gpio/consumer.h instead?

I really don't like these kinds of things at all.

If GPIO is required to fully program the hardware properly,
the smc91x driver should have it as a dependency.