Commit df61b366af26 ("pinctrl: core: Use delayed work for hogs") caused a
regression at least with sh-pfc that is also a GPIO controller as
noted by Geert Uytterhoeven <geert@linux-m68k.org>.
As the original pinctrl_register() has issues calling pin controller
driver functions early before the controller has finished registering,
we can't just revert commit df61b366af26. That would break the drivers
using GENERIC_PINCTRL_GROUPS or GENERIC_PINMUX_FUNCTIONS.
So let's fix the issue with the following steps as a single patch:
1. Revert the late_init parts of commit df61b366af26.
The late_init clearly won't work and we have to just give up
on fixing pinctrl_register() for GENERIC_PINCTRL_GROUPS and
GENERIC_PINMUX_FUNCTIONS.
2. Split pinctrl_register() into two parts
By splitting pinctrl_register() into pinctrl_init_controller()
and pinctrl_create_and_start() we have better control over when
it's safe to call pinctrl_create().
3. Introduce a new pinctrl_register_and_init() function
As suggested by Linus Walleij <linus.walleij@linaro.org>, we
can just introduce a new function for the controllers that need
pinctrl_create() called later.
4. Convert the four known problem cases to use new function
Let's convert pinctrl-imx, pinctrl-single, sh-pfc and ti-iodelay
to use the new function to fix the issues. The rest of the drivers
can be converted later. Let's also update Documentation/pinctrl.txt
accordingly because of the known issues with pinctrl_register().
Fixes: df61b366af26 ("pinctrl: core: Use delayed work for hogs")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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