Re: MMC/regulator boot hang in -next

From: John Stultz
Date: Mon Nov 02 2015 - 18:04:35 EST


On Mon, Nov 2, 2015 at 2:58 PM, Mark Brown <broonie@xxxxxxxxxx> wrote:
> On Mon, Nov 02, 2015 at 02:03:14PM -0800, John Stultz wrote:
>
>> Might the problem be here that we lock the supply in set_voltage, then
>> if we call _regulator_get_voltage on the supply later, we try to grab
>> the same lock and we're stuck?
>
> No, the internal get voltage call shouldn't be locking in the first
> place (and indeed it doesn't do so AFAICT?).

drivers/regulator/core.c: @3063
static int _regulator_get_voltage(struct regulator_dev *rdev)
{
int sel, ret;

if (rdev->desc->ops->get_voltage_sel) {
...
} else if (rdev->supply) {
ret = regulator_get_voltage(rdev->supply); <-----
} else {

Where _regulator_get_voltage() is called from
regulator_set_voltage_unlocked(), called from regulator_set_voltage().

thanks
-john
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