Re: [PATCH v2 0/6] coresight: Add format attribute for setting the timestamp interval

On Thu, Aug 14, 2025 at 11:49:51AM +0100, James Clark wrote:

[...]

This is added as an event format attribute, rather than a Coresight config because it's something that the driver is already configuring automatically in Perf mode with any unused counter, so it's not possible to modify this with a config.

Tested on Juno-r2 for this series:

# /mnt/build/perf record -e cs_etm/timestamp=1,ts_level=15/ -- ls # /mnt/build/perf script -D | grep I_TIMESTAMP | wc

1305 11745 83337

# /mnt/build/perf record -e cs_etm/timestamp=1,ts_level=0/ -- ls # /mnt/build/perf script -D | grep I_TIMESTAMP | wc

120668 1086012 7705024

We can see a small counter (2 ^ 0 = 1) that records significant timestamp packets.

Tested-by: Leo Yan leo.yan@arm.com