Hi,
On Thu, 9 Feb 2023 at 03:02, Jinlong Mao quic_jinlmao@quicinc.com wrote:
On 2/9/2023 12:36 AM, Suzuki K Poulose wrote:
On 08/02/2023 16:20, Mike Leach wrote:
Quick correction - you need to look for enable_source / enable_sink files and disable those that are currently '1'
Mike
On Wed, 8 Feb 2023 at 16:16, Mike Leach mike.leach@linaro.org wrote:
Hi
As this is a sysfs only update - would it not be easier to simply use a shell script to iterate through coresight/devices/ looking for disable_source / disable_sink files and setting those accordingly?
See tools/perf/tests/shell/test_arm_coresight.sh for an example of a script that does similar iteration to test coresight in perf
+1
Suzuki
Hi Mike & Suzuki,
Sometimes user just want to have some quick test from PC with adb commands. It is very easy to reset all sources and sinks' status by command below. echo 1 > /sys/bus/coresight/reset_source_sink
Users of coresight via sysfs will have to know how to use the coresight infrastructure in order to enable the sources and sinks in the first place - e.g echo 1 > /sys/bus/coresight/devices/tmc_etr0/enable_sink echo 1 > /sys/bus/coresight/devices/etm0/enable_source
Given that they are aware of which sources and sinks they enabled - disabling them should be simple.
Preparing the script for test is not easy for users who are not familiar with the coresight framework.
If there is a genuine use case were a user has opened so many sources on the command line that they need a simpler way of closing them than repeating the enabled commands with an echo 0 > ... then any script could be shipped as part of kernel/tools/coresight or kernel/samples/coresight - they would not have to write it themselves, and just run it from the command line - for example :- ./kernel/tools/coresight/scripts/sysfs_disable_sources_and_sinks.sh
Realistically users will only try out a couple of devices as the usefulness of the sysfs interface is really limited to testing or board bring up. Any complex use with sysfs - as in the coresight tests I mentioned earlier is really going to be done by scripting.
Regards
Mike
Thanks Jinlong Mao