From: Gianluca Anzolin Date: Tue, 27 Aug 2013 16:28:46 +0000 (+0200) Subject: Bluetooth: don't release the port in rfcomm_dev_state_change() X-Git-Tag: v3.12-rc4~30^2~39^2^2~16^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29cd718beba999bda4bdbbf59b5a4d25c07e1547;p=pandora-kernel.git Bluetooth: don't release the port in rfcomm_dev_state_change() When the dlc is closed, rfcomm_dev_state_change() tries to release the port in the case it cannot get a reference to the tty. However this is racy and not even needed. Infact as Peter Hurley points out: 1. Only consider dlcs that are 'stolen' from a connected socket, ie. reused. Allocated dlcs cannot have been closed prior to port activate and so for these dlcs a tty reference will always be avail in rfcomm_dev_state_change() -- except for the conditions covered by #2b below. 2. If a tty was at some point previously created for this rfcomm, then either (a) the tty reference is still avail, so rfcomm_dev_state_change() will perform a hangup. So nothing to do, or, (b) the tty reference is no longer avail, and the tty_port will be destroyed by the last tty_port_put() in rfcomm_tty_cleanup. Again, no action required. 3. Prior to obtaining the dlc lock in rfcomm_dev_add(), rfcomm_dev_state_change() will not 'see' a rfcomm_dev so nothing to do here. 4. After releasing the dlc lock in rfcomm_dev_add(), rfcomm_dev_state_change() will 'see' an incomplete rfcomm_dev if a tty reference could not be obtained. Again, the best thing to do here is nothing. Any future attempted open() will block on rfcomm_dev_carrier_raised(). The unconnected device will exist until released by ioctl(RFCOMMRELEASEDEV). The patch removes the aforementioned code and uses the tty_port_tty_hangup() helper to hangup the tty. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan --- Reading git-diff-tree failed