Since Add/Remove Device perform the page scan updates independently
from the HCI command completion we've introduced a potential race when
multiple mgmt commands are queued. Doing the page scan updates through
the req_workqueue ensures that the state changes are performed in a
race-free manner.

At the same time, to make the request helper more widely usable,
extend it to also cover Inquiry Scan changes since those are behind
the same HCI command. This is also reflected in the new name of the
API as well as the work struct name.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Since discovery also deals with LE scanning it makes sense to move it
behind the same req_workqueue as other LE scanning changes. This also
simplifies the logic since we do many of the actions in a synchronous
manner.

Part of this refactoring is moving hci_req_stop_discovery() to
hci_request.c. At the same time the function receives support for
properly handling the STOPPING state since that's the state we'll be
in when stopping through the req_workqueue.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In some circumstances it may be useful to abort the request through
checks done in the request callback. To make the feature possible this
patch changes the return value of the request callback from void to
int and aborts the request if a non-zero value is returned.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There are no more external users so this API can be made private.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In some cases it may be important to get the exact HCI status rather
than the converted HCI-to-errno value. Add an optional return
parameter to the hci_req_sync() API to allow for this. Since there are
no good HCI translation candidates for cancelation and timeout, use
the "unknown" status code for those cases.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Instead of firing off a simple async request queue all background scan
updates through req_workqueue and use hci_req_sync() there to ensure
that no two updates overlap with each other.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Prepare hci_request.c to have code for doing synchronous HCI requests,
such as LE scanning or advertising changes. The necessary work
callbacks will be set up in hci_request_setup() and cleaned up in
hci_request_cancel_all(). The former is used when an HCI device get
registered, and the latter each time it is powered off (or
unregistered).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

To make it clear which HCI request APIs target specifically
synchronous requests, add 'sync' to the API names.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

hci_request.c is a more natural place for the synchronous request
handling. Furthermore, we will soon need access to some of the
previously private-to-hci_core.c functions from hci_request.c.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

There are several different places needing to make sure that a
connection gets disconnected or canceled. The exact action needed
depends on the connection state, so centralizing this logic can save
quite a lot of code duplication.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds a second possible callback for HCI requests where the
callback will receive the full skb of the last successfully completed
HCI command. This API is useful for cases where we want to use a request
to read some data and the existing hci_event.c handlers do not store it
e.g. in the hci_dev struct.

The reason the patch is a bit bigger than just adding the new API is
because the hci_req_cmd_complete() functions required some refactoring
to enable it: now hci_req_cmd_complete() is simply used to request the
callback pointers if any, and the actual calling of them happens from a
single place at the end of hci_event_packet(). The reason for this is
that we need to pass the original skb (without any skb_pull, etc
modifications done to it) and it's simplest to keep track of it within
the hci_event_packet() function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Many places using hci_update_background_scan() try to synchronize
whatever they're doing with the help of hci_request callbacks. However,
since the hci_update_background_scan() function hasn't so far accepted a
hci_request pointer any commands triggered by it have been left out by
the synchronization. This patch modifies the API in a similar way as was
done for hci_update_page_scan, i.e. there's a variant that takes a
hci_request and another one that takes a hci_dev.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

None of the hci_request related things in net/bluetooth/hci_core.h are
needed anywhere outside of the core bluetooth module. This patch creates
a new net/bluetooth/hci_request.c file with its corresponding h-file and
moves the functionality there from hci_core.c and hci_core.h.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>