• Tony Lindgren's avatar
    pinctrl: core: Fix regression caused by delayed work for hogs · 950b0d91
    Tony Lindgren authored
    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: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
    Cc: Gary Bisson <gary.bisson@boundarydevices.com>
    Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
    Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
    Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    950b0d91
pinctrl.txt 50.3 KB