coresight: Fix reference count for software sources
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Mon, 5 Jun 2017 20:15:03 +0000 (14:15 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 13 Apr 2018 17:48:25 +0000 (19:48 +0200)
commit41830b8672a801adb74486d37fee4c35c9ca42b2
tree29fa071a7654391532bf772bf4ccdc23b6f35f53
parent577438f5774154305c80a5f5a4a66cd7c4a2ca39
coresight: Fix reference count for software sources

[ Upstream commit 022aa1a81b778789ee7cf3124595854276a0330d ]

For software sources (i.e STM), there could be multiple agents
generating the trace data, unlike the ETMs. So we need to
properly do the accounting for the active number of users
to disable the device when the last user goes away. Right
now, the reference counting is broken for sources as we skip
the actions when we detect that the source is enabled.

This patch fixes the problem by adding the refcounting for
software sources, even when they are enabled.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Reported-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/coresight/coresight.c