On Tue, Feb 23, 2016 at 02:15:21PM +0000, Jon Hunter wrote:
Hi Krzysztof,
On 23/02/16 13:56, Krzysztof Adamski wrote:
On Tue, Feb 23, 2016 at 01:22:38PM +0000, Jon Hunter wrote:
Hi Mark, Krzysztof,
It appears that commit daad134d6649 ("regulator: core: Request GPIO
before creating sysfs entries") breaks boot on tegra124-nyan-big in
-next today.
Looking at the change, it does not appear that the exit path has been
updated correctly and so if a regulator is deferred then there is a
crash in the exit path. I am not sure that there is a simple way to
workaround this because of fix from commit 53032dafc6b9 ("regulator
core: fix double-free in regulator_register() error path") unless we
move regulator_ena_gpio_free() into regulator_dev_release().
Hi Jon,
You are totally right about the problem but I can't see why changing
"goto wash" to "goto clean" in error path of regulator_ena_gpio_request
is not enough. What am I missing?
So device_unregister() will call regulator_dev_release() which will free
rdev (see commit 53032dafc6b9). However, rdev is needed by
regulator_ena_gpio_free() and therefore, we need to call
regulator_ena_gpio_free() before we call device_unregister(). So
swapping the order will cause other problems.
One possibility would be to move regulator_ena_gpio_free() into
regulator_dev_release(). If did we could remove the
regulator_ena_gpio_free() from regulator_unregister(). However, I have
not looked at that in great detail. May be Mark can comment if that
would be ok.
But in case of regulator_ena_gpio_free() failure, we shouldn't call
device_unregister() at all, since it was not yet registered and that is
exactly what "clean" does.
Best regards,
Krzysztof Adamski
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