[U-Boot] [PATCH v2 1/2] dm: core: device: switch off power domain after device removal

[Simon Glass <sjg@chromium.org>]

Hi Anatolij,

On Wed, 31 Jul 2019 at 10:01, Anatolij Gustschin <agust@denx.de> wrote:
>
> Hi Simon,
>
> On Thu, 18 Jul 2019 09:22:20 -0600
> Simon Glass sjg at chromium.org wrote:
> ...
> > > >  drivers/core/device-remove.c | 9 +++++++++
> > > >  include/dm/device.h          | 6 ++++++
> > > >  2 files changed, 15 insertions(+)
> >
> > Unfortunately this causes a test failure (make qcheck). Can you please
> > take a look?
>
> The dm power_domain test worked, but later when
>  dm_test_destroy()
>   -> uclass_destroy()
> removes devices, first 'power-domain' device is removed, then
> the 'power-domain-test' device. When removing the latter, we run
>
>  if (!power_domain_get(dev, &pd))
>        power_domain_off(&pd);
>
> and this probes sandbox_power_domain driver for 'power-domain' device
> activating this device again. Then 'power-domain-test' device is removed,
> but 'power-domain' is active. When unbinding it later, we get this error
> in device_unbind():
>
>         if (dev->flags & DM_FLAG_ACTIVATED)
>                 return -EINVAL;

This is because you are not allowed to unbind an active device. You
must deactivate it (device_remove()) first.

>
> Following will fix it:
>
> diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c
> index 586fadee0a..fadb05c944 100644
> --- a/drivers/core/device-remove.c
> +++ b/drivers/core/device-remove.c
> @@ -64,7 +64,8 @@ int device_unbind(struct udevice *dev)
>         if (!dev)
>                 return -EINVAL;
>
> -       if (dev->flags & DM_FLAG_ACTIVATED)
> +       if (dev->flags & DM_FLAG_ACTIVATED &&
> +           device_get_uclass_id(dev) != UCLASS_POWER_DOMAIN)
>                 return -EINVAL;
>
>         if (!(dev->flags & DM_FLAG_BOUND))
>
> But I'm not sure if this it the correct approach. What do you think?

That doesn't look right to me. Power supplies should be removed before
being unbound, just like any other device.

Regards,
Simon