[U-Boot] [PATCH 1/4] configs: opos6uldev: undef CONFIG_POWER_DOMAIN when SPL_BUILD

[Simon Glass]

Hi Peng,

On 24 July 2018 at 20:57, Peng Fan <peng.fan at nxp.com> wrote:
> Hi Simon,
>
>> -----Original Message-----
>> From: sjg at google.com [mailto:sjg at google.com] On Behalf Of Simon Glass
>> Sent: 2018年7月25日 10:46
>> To: Peng Fan <peng.fan at nxp.com>
>> Cc: U-Boot Mailing List <u-boot at lists.denx.de>; dl-linux-imx
>> <linux-imx at nxp.com>; Sébastien Szymanski
>> <sebastien.szymanski at armadeus.com>; Stefano Babic <sbabic at denx.de>
>> Subject: Re: [PATCH 1/4] configs: opos6uldev: undef CONFIG_POWER_DOMAIN
>> when SPL_BUILD
>>
>> Hi Peng,
>>
>> On 24 July 2018 at 01:45, Peng Fan <peng.fan at nxp.com> wrote:
>> > Because CONFIG_POWER_DOMAIN is enabled in defconfig, however
>> > driver/power/domain is not built for SPL, there is build failure when
>> > power_domain_on added to device_probe.
>> > Because power domain is not needed in SPL, let's undef it.
>> >
>> > Signed-off-by: Peng Fan <peng.fan at nxp.com>
>> > Cc: "Sébastien Szymanski" <sebastien.szymanski at armadeus.com>
>> > Cc: Stefano Babic <sbabic at denx.de>
>> > ---
>> >
>> > Need to find a way to avoid SPL build failure in future patch, but in
>> > this patchset let's undef CONFIG_POWER_DOMAIN first, because it is not
>> > needed.
>> >
>> >  include/configs/opos6uldev.h | 1 +
>> >  1 file changed, 1 insertion(+)
>>
>> This should be handled by adding an SPL_POWER_DOMAIN option and
>> converting existing uses to CONFIG_IS_ENABLED(POWER_DOMAIN)
>
> The opos6uldev_defconfig has "CONFIG_POWER_DOMAIN=y", so when building
> SPL, this macro is still effective.
> Opos6uldev compiles driver/core/device.c which includes power-domain.h in my later patch.
> Because driver/power/domain is not built for SPL, so build failure for SPL.
>
> The simple method for now is to undef CONFIG_POWER_DOMAIN for SPL build.
> If use CONFIG_IS_ENABLED, the undef CONFIG_POWER_DOMAIN will not be detected in Kconfig.
>
> Simply introduce SPL_POWER_DOMAIN could not fix this issue. Need to let SPL choose CONFIG_SPL_POWER_DOMAIN,
> but not CONFIG_POWER_DOMAIN, I do not have a clear idea on how.

Here's how it works:

1. Have two separate Kconfig options: CONFIG_POWER_DOMAIN and
CONFIG_SPL_POWER_DOMAIN
2. Enable CONFIG_POWER_DOMAIN in the board config, but not
CONFIG_SPL_POWER_DOMAIN
3. Use CONFIG_IS_ENABLED(POWER_DOMAIN) everywhere (with if() or #if)
4. Now, U-Boot proper will support POWER_DOMAIN, but SPL will not

The #undef mechanism is the old way of doing it, before we had CONFIG_IS_ENABLED

Regards,
Simon