| Message ID | 20210710103819.12532-3-adrian.hunter@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | driver core: Add ability to delete device links of unregistered devices | expand |
On Sat, Jul 10, 2021 at 12:38 PM Adrian Hunter <adrian.hunter@intel.com> 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@intel.com> > 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@kernel.org> to the resulting combo patch. > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > 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 >
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"); }
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 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@intel.com> Fixes: b294ff3e34490 ("scsi: ufs: core: Enable power management for wlun") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- drivers/base/core.c | 2 ++ 1 file changed, 2 insertions(+)