tree e5f4f2ecd25649b5d47589ba2cf919c4e92ed222
parent 10c6c383e43565c9c6ec07ff8eb2825f8091bdf0
author Russ Gorby <russ.gorby@intel.com> 1344861880 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1345143810 -0700

n_gsm: added interlocking for gsm_data_lock for certain code paths

There were some locking holes in the management of the MUX's
message queue for 2 code paths:
1) gsmld_write_wakeup
2) receipt of CMD_FCON flow-control message
In both cases gsm_data_kick is called w/o locking so it can collide
with other other instances of gsm_data_kick (pulling messages tx_tail)
or potentially other instances of __gsm_data_queu (adding messages to tx_head)

Changed to take the tx_lock in these 2 cases

Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Tested-by: Yin, Fengwei <fengwei.yin@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Riding School <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>