* Pavel Machek [off-list ref] [160113 11:13]:

On Mon 2016-01-11 14:10:23, Kishon Vijay Abraham I wrote:

quoted

'select' is generally not recommended since it selects a config without
caring for the dependency. With adding 'depends on', MMC won't be enabled and
will end up in the same problem.

Well... it really should "depend on". Not ideal, but you'll likely
realize what went on.

Silently compiling known-bad kernel is ... well.. bad.

Force selects will lead into build errors sooner or later.

quoted

Tony has already added a Documentation noting that CONFIG_REGULATOR_PBIAS
should be enabled for MMCs to work.
commit d8e1f5ed11a39a68da00f05000466c4f6db4456e
Author: Tony Lindgren [off-list ref]
Date:   Mon Oct 12 16:19:54 2015 -0700

    Documentation: ARM: List new omap MMC requirements

Maybe we should also make the error message a little more verbose to tell the
user that CONFIG_REGULATOR_PBIAS be selected?

That would help.

As would #error if we recognize broken config.

Can't we just add a check to the omap_hsmmc.c? In cases where
MMC1 has the PBIAS regulator configured but not available, print
an error about missing CONFIG_REGULATOR_PBIAS error and return
-EPROBE_DEFER?

Regards,

Tony