[BUG] omap: mfd/regulator: twl/core: init order

[Christoph Fritz]

On Mon, 2013-04-15 at 13:20 +0300, Grygorii Strashko wrote:
> On 04/13/2013 09:27 PM, Christoph Fritz wrote:
> > Hi
> >
> >   while testing an omap3 board with device tree support I stumbled upon a
> > bug which is due to wrong initialization order of twl-core and
> > twl-regulator (I suppose): In the boot process they get loaded way too
> > late so that a lot of drivers before where configured wrong or just
> > refuse to load.
> >
> > For example the real time clock driver: The RTC kicks in way before
> > twl_probe() and due to that it configures its register map wrong
> > (at this time twl_priv->twl_id isn't configured yet).
> >
> > Another example is the omap display subsystem. It (DSS) fails loading
> > while trying to register some not yet existent regulators and because it
> > lacks EPROBE_DEFER.
> >
> > USB and MMC is also not working and I'm suspicious of the same cause.
> >
> > Any ideas?
> Hi Christoph,
> 
> It happens, because I2C probes execution  have been deferred due to
> "pinctrl-single" driver (, which is not ready at i2c bus initialization 
> time:
> 
> [    0.525939] omap_i2c 48070000.i2c: could not find pctldev for node 
> /ocp/pinmux at 4a100040/pinmux_i2c1_pins, deferring probe
> [    0.526000] platform 48070000.i2c: Driver omap_i2c requests probe 
> deferral
> [    0.526062] omap_i2c 48072000.i2c: could not find pctldev for node 
> /ocp/pinmux at 4a100040/pinmux_i2c2_pins, deferring probe
> [    0.526092] platform 48072000.i2c: Driver omap_i2c requests probe 
> deferral
> [    0.526153] omap_i2c 48060000.i2c: could not find pctldev for node 
> /ocp/pinmux at 4a100040/pinmux_i2c3_pins, deferring probe
> [    0.526184] platform 48060000.i2c: Driver omap_i2c requests probe 
> deferral
> [    0.526245] omap_i2c 48350000.i2c: could not find pctldev for node 
> /ocp/pinmux at 4a100040/pinmux_i2c4_pins, deferring probe
> [    0.526275] platform 48350000.i2c: Driver omap_i2c requests probe 
> deferral
> 
> I think following change should fix it, could you try it, pls:
> diff --git a/drivers/pinctrl/pinctrl-single.c 
> b/drivers/pinctrl/pinctrl-single.c
> index 5c32e88..b2a9d4b 100644
> --- a/drivers/pinctrl/pinctrl-single.c
> +++ b/drivers/pinctrl/pinctrl-single.c
> @@ -1014,7 +1014,18 @@ static struct platform_driver pcs_driver = {
>          },
>   };
> 
> -module_platform_driver(pcs_driver);
> +static int __init pcs_driver_drv_init(void)
> +{
> +       return platform_driver_register(&pcs_driver);
> +}
> +postcore_initcall(pcs_driver_drv_init);
> +
> +static void __exit pcs_driver_drv_exit(void)
> +{
> +       platform_driver_unregister(&pcs_driver);
> +}
> +module_exit(pcs_driver_drv_exit);
> +

Hi Grygorii,
 thanks - indeed it does fix the problem. I checked at least the rtc
which is now configured right and working :-)

Do you consider the patch above as a hack or will it go mainline?

 Thanks
  -- Christoph