coresight: tmc: getting rid of multiple read access

Browse source

Allowing multiple readers to access the trace data simultaniously
via sysFS provides no shortage of opportunity for race condition,
mandates two variable to be maintained (drvdata::read_count and
drvdata::reading), makes the code complex and provide little
advantages, if any.

This patch streamlines the read process by restricting trace data
access to a single user.  That way drvdata::read_count can
be eliminated and race conditions (along with faulty error handling)
in function tmc_open() and tmc_release() eliminated.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Mathieu Poirier 2016-05-03 11:33:53 -06:00 • committed by Greg Kroah-Hartman

parent de5461970b

commit f74debbea0

4 changed files with 18 additions and 17 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

5

drivers/hwtracing/coresight/coresight-tmc-etf.c

View file

4

drivers/hwtracing/coresight/coresight-tmc-etr.c

View file

24

drivers/hwtracing/coresight/coresight-tmc.c

View file

2

drivers/hwtracing/coresight/coresight-tmc.h

View file