Re: [PATCH V3 2/3] driver core: Add ability to delete device links of unregistered devices

[Rafael J. Wysocki]

On Sat, Jul 10, 2021 at 12:38 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> Managed device links are deleted by device_del(). However it is possible to
> add a device link to a consumer before device_add(), and then discover an

I would say "discovering an error"

> error prevents the device from being used. In that case normally references
> to the device would be dropped and the device would be deleted. However the
> device link holds a reference to the device, so the device link and device
> remain indefinitely (unless the supplier is deleted).
>
> Amend device link removal to accept removal of a link with an
> unregistered consumer device.
>
> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Fixes: b294ff3e34490 ("scsi: ufs: core: Enable power management for wlun")

This patch by itself doesn't fix the above one, so the tag doesn't
seem to be suitable here.

Frankly, I would consider folding it into the third patch in the
series in which case please feel free to add

Reviewed-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>

to the resulting combo patch.

> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
>  drivers/base/core.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 2de8f7d8cf54..983e895d4ced 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -887,6 +887,8 @@ static void device_link_put_kref(struct device_link *link)
>  {
>         if (link->flags & DL_FLAG_STATELESS)
>                 kref_put(&link->kref, __device_link_del);
> +       else if (!device_is_registered(link->consumer))
> +               __device_link_del(&link->kref);
>         else
>                 WARN(1, "Unable to drop a managed device link reference\n");
>  }
> --
> 2.17.1
>