Hi, On Thu, 9 Feb 2023 at 03:02, Jinlong Mao <quic_jinlmao@xxxxxxxxxxx> 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@xxxxxxxxxx> 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 > > > > > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
