Hi Leo
On Fri, 3 Oct 2025 at 15:50, Leo Yan leo.yan@arm.com wrote:
On Fri, Oct 03, 2025 at 10:38:24AM +0100, Mike Leach wrote:
Hi Leo,
The CTI PM code was initially set up before the CTI was a helper device.
If the core bound CTIs, which are helpers to the core bound ETMs, are disabled as part of the path disable helpers, then I think the CTI specific PM code might be redundant.
If it is not, then should this not hook into the generic PM code in coresight-core.c?
Correct, CTI devices will be managed as a part of path in coresight-core.c (See patches 26 and 31).
However, we still need cti_pm_setup() - when a CPU bound CTI is enabled via CTI's sysfs interface, in this case, no path is enabled but purely CTI device is enabled.
A side topic not related to this series, I am curious if we can remove the enable/disable knobs in coresight-cti-sysfs.c, then CTI will only work as helper. This can significantly simplify the CTI driver.
Not all CTIs are on the path, but potentially even non-path CTIs can introduce signal inputs to the CTM that trigger events in the trace path.
Mike
Thanks, Leo