[PATCH v9 02/24] v4l: async: Remove re-probing support

Sakari Ailus
2017-09-08T13:11:53Z

Remove V4L2 async re-probing support. The re-probing support has been
there to support cases where the sub-devices require resources provided by
the main driver's hardware to function, such as clocks.

Reprobing has allowed unbinding and again binding the main driver without
explicilty unbinding the sub-device drivers. This is certainly not a
common need, and the responsibility will be the user's going forward.

An alternative could have been to introduce notifier specific locks.
Considering the complexity of the re-probing and that it isn't really a
solution to a problem but a workaround, remove re-probing instead.

Signed-off-by: Sakari Ailus <sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
drivers/media/v4l2-core/v4l2-async.c | 54 ------------------------------------
1 file changed, 54 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index d741a8e0fdac..e109d9da4653 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -198,78 +198,24 @@ EXPORT_SYMBOL(v4l2_async_notifier_register);
void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
{
struct v4l2_subdev *sd, *tmp;
- unsigned int notif_n_subdev = notifier->num_subdevs;
- unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
- struct device **dev;
- int i = 0;

if (!notifier->v4l2_dev)
return;

- dev = kvmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
- if (!dev) {
- dev_err(notifier->v4l2_dev->dev,
- "Failed to allocate device cache!\n");
- }
-
mutex_lock(&list_lock);

list_del(&notifier->list);

list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
- struct device *d;
-
- d = get_device(sd->dev);
-
v4l2_async_cleanup(sd);

- /* If we handled USB devices, we'd have to lock the parent too */
- device_release_driver(d);
-
if (notifier->unbind)
notifier->unbind(notifier, sd, sd->asd);
-
- /*
- * Store device at the device cache, in order to call
- * put_device() on the final step
- */
- if (dev)
- dev[i++] = d;
- else
- put_device(d);
}

mutex_unlock(&list_lock);

- /*
- * Call device_attach() to reprobe devices
- *
- * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
- * executed.
- */
- while (i--) {
- struct device *d = dev[i];
-
- if (d && device_attach(d) < 0) {
- const char *name = "(none)";
- int lock = device_trylock(d);
-
- if (lock && d->driver)
- name = d->driver->name;
- dev_err(d, "Failed to re-probe to %s\n", name);
- if (lock)
- device_unlock(d);
- }
- put_device(d);
- }
- kvfree(dev);
-
notifier->v4l2_dev = NULL;
-
- /*
- * Don't care about the waiting list, it is initialised and populated
- * upon notifier registration.
- */
}
EXPORT_SYMBOL(v4l2_async_notifier_unregister);

--
2.11.0

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