Re: [PATCH V3 2/3] driver core: Add ability to delete device links of unregistered devices
From: Rafael J. Wysocki
Date: Wed Jul 14 2021 - 14:26:30 EST
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);
> WARN(1, "Unable to drop a managed device link reference\n");