On 09/10/2013 11:53 AM, Guenter Roeck wrote: > On 09/09/2013 08:40 PM, Stephen Warren wrote: >> On 09/09/2013 09:36 PM, Guenter Roeck wrote: >>> On 09/09/2013 08:22 PM, Wei Ni wrote: >>>> On 09/09/2013 11:50 PM, Guenter Roeck wrote: >>>>> On Mon, Sep 09, 2013 at 02:50:22PM +0100, Mark Brown wrote: >>>>>> On Mon, Sep 09, 2013 at 04:34:43AM -0700, Guenter Roeck wrote: >>>>>>> On 09/09/2013 04:12 AM, Mark Brown wrote: >>>>>>>> On Mon, Sep 09, 2013 at 06:29:11PM +0800, Wei Ni wrote: >>>>>> >>>>>>>> This doesn't look good, it is going to ignore actual errors - I >>>>>>>> *really* >>>>>>>> doubt that vcc is optional, it looks like it's the main power >>>>>>>> supply for >>>>>>>> the device. You should use normal regulator_get(), _optional() is >>>>>>>> for >>>>>>>> supplies which could physically not be provided in a system (eg, >>>>>>>> if the >>>>>>>> device can generate them internally if required). >>>>>> >>>>>>> Then he'll have to make sure that all devicetree files in the system >>>>>>> contain references to this regulator. >>>>>> >>>>>> Or get the patches applied on top of the code that'll be going in this >>>>>> cycle implementing get_optional() properly - when that's done the >>>>>> default will be to provide a dummy supply for regulator_get(). If you >>>>>> ack the patch I'd be happy to carry it. >>>>>> >>>>> Jean will have to ack it. >>>>> >>>> I think it's better to use get_optional(), and ignore the errors except >>>> -EPROBE_DEFER. Because many platform may always power on this device, >>>> and will not provide regulator for it, so if we get errors from >>>> regulator subsystem and return it directly, then the probe() can't be >>>> implemented, this driver can't work properly, even though it can work >>>> without regulator support. >>>> Mark, do you mean you have patches for regulator_get_optional() and >>>> regulator_get()? >>>> >>> >>> My understanding is that by adding regulator support you essentially >>> committed to adding regulators (if necessary dummy ones) for this driver >>> to all those platforms. This is quite similar to other drivers in the >>> same situation. Once you start along that route, you'll have to go it >>> all the way. >> >> By using regulator_get_optional(), the regulator should be optional, >> hence you only have to add it to platforms that need it. >> > > Earlier comments suggest that this is not the intended use case for > regulator_get_optional(). So I just need to use the regulator_get() instead, is it right? > > Guenter > -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
