stm class: Guard output assignment against concurrency
authorAlexander Shishkin <alexander.shishkin@linux.intel.com>
Mon, 15 Feb 2016 17:12:06 +0000 (19:12 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 20 Feb 2016 22:09:14 +0000 (14:09 -0800)
commitcde4ad8368840e414ecf67db258fe1dabaa5fd2e
tree17f5dee33891f9b3aed3e10709a36d285c59b892
parent1810f2c44817c74ca3d05d1e3981e3a2e2ceb6f5
stm class: Guard output assignment against concurrency

It is possible to concurrently assign the same output (a character
device writer or an stm_source device) to different stm devices,
which sets off a strategically placed warning in stm_output_assign().

To avoid this, use a spinlock to serialize (un)assignments between
outputs and stm devices.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/stm/core.c
drivers/hwtracing/stm/stm.h