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FROMLIST: v4l: async: Remove re-probing support

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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@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
(cherry picked from commit 382da6accc6808123971e0f257eae2a2110d8486)
https://git.linuxtv.org/sailus/media_tree.git/log/?h=010f7f4393fd
http://www.spinics.net/lists/linux-media/msg122688.html
Signed-off-by: Marc Herbert <marc.herbert@intel.com>

BUG=b:64133998
TEST=media device topology shows subdevs registered successfully
TEST=no camera regression

Change-Id: Ic19af101230e335cb00c575d59a17040629aa72b
Reviewed-on: https://chromium-review.googlesource.com/693685
Commit-Ready: Tomasz Figa <tfiga@chromium.org>
Tested-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
This commit is contained in:
Sakari Ailus
2017-09-05 15:11:59 +03:00
committed by Tao Huang
parent b5fb9529d3
commit f22da32f4a
1 changed files with 1 additions and 53 deletions
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54
drivers/media/v4l2-core/v4l2-async.c
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@@ -202,78 +202,26 @@ 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 = kmalloc_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);
list_move(&sd->async_list, &subdev_list);
}
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);
}
kfree(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);