• Marcel Holtmann's avatar
    Bluetooth: Fix race condition with user channel and setup stage · 781f899f
    Marcel Holtmann authored
    During the initial setup stage of a controller, the low-level transport
    is actually active. This means that HCI_UP is true. To avoid toggling
    the transport off and back on again for normal operation the kernel
    holds a grace period with HCI_AUTO_OFF that will turn the low-level
    transport off in case no user is present.
    
    The idea of the grace period is important to avoid having to initialize
    all of the controller twice. So legacy ioctl and the new management
    interface knows how to clear this grace period and then start normal
    operation.
    
    For the user channel operation this grace period has not been taken into
    account which results in the problem that HCI_UP and HCI_AUTO_OFF are
    set and the kernel will return EBUSY. However from a system point of
    view the controller is ready to be grabbed by either the ioctl, the
    management interface or the user channel.
    
    This patch brings the user channel to the same level as the other two
    entries for operating a controller.
    Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
    Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
    Cc: stable@vger.kernel.org
    781f899f
hci_sock.c 30.1 KB