Re: [PATCH 3/8] gpio: zynq: Shift zynq_gpio_init() to subsys_initcall level

From: Linus Walleij
Date: Tue Aug 22 2017 - 09:02:39 EST


On Mon, Aug 14, 2017 at 4:15 PM, Michal Simek <michal.simek@xxxxxxxxxx> wrote:

>> Can't you just move it all the way to device_initcall and
>> simply use the standard module init macros?
>> builtin_platform_driver(), module_platform_driver()?
>
> When I grep the kernel I see this
>
> [linux](master)$ git grep "^core_initcall" drivers/gpio/ | wc -l
> 1
> [linux](master)$ git grep "^postcore_initcall" drivers/gpio/ | wc -l
> 12
> [linux](master)$ git grep "^arch_initcall" drivers/gpio/ | wc -l
> 2
> [linux](master)$ git grep "^subsys_initcall" drivers/gpio/ | wc -l
> 33
> [linux](master)$ git grep "^device_initcall" drivers/gpio/ | wc -l
> 4
>
>
> [linux](master)$ git grep "^core_initcall" drivers/pinctrl/ | wc -l
> 6
> [linux](master)$ git grep "^postcore_initcall" drivers/pinctrl/ | wc -l
> 7
> [linux](master)$ git grep "^arch_initcall" drivers/pinctrl/ | wc -l
> 62
> [linux](master)$ git grep "^subsys_initcall" drivers/pinctrl/ | wc -l
> 12
> [linux](master)$ git grep "^device_initcall" drivers/pinctrl/ | wc -l
> 0
>
> Majority of gpio drivers are in subsys_initcall and pinctrl in
> arch_initcall.

The majority is likely wrong, we don't vote about what is the
best code quality luckily :D

You do not see a lot of device_initicall because in the majority
of cases these come implicitly from module_platform_driver(),
builtin_platform_driver_probe() or builtin_platform_driver()
see include/linux/platform_device.h

> It doesn't mean that I have strong opinion about doing
> this change. I have also read internal tracking system and it is not
> fully clear if this is fixing any issue rather than removing on
> deferring probe message.

I think you can make it into module_platform_driver() please
try that approach.

Yours,
Linus Walleij