On 14/11/2025 5:02 am, Randy Dunlap wrote:

On 11/12/25 7:22 AM, James Clark wrote:

...

Document how the new field is used, maximum value and the interaction with SYNC timestamps.

Signed-off-by: James Clark james.clark@linaro.org

Documentation/trace/coresight/coresight.rst | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/Documentation/trace/coresight/coresight.rst b/Documentation/trace/coresight/coresight.rst index 806699871b80..80b5ed09d69b 100644 --- a/Documentation/trace/coresight/coresight.rst +++ b/Documentation/trace/coresight/coresight.rst @@ -613,8 +613,19 @@ They are also listed in the folder /sys/bus/event_source/devices/cs_etm/format/ - Session local version of the system wide setting: :ref:`ETM_MODE_RETURNSTACK <coresight-return-stack>` * - timestamp

• - Session local version of the system wide setting: :ref:`ETMv4_MODE_TIMESTAMP
  

•   <coresight-timestamp>`
  

• - Controls generation and interval of timestamps.
  

•   0 = off, 1 = maximum interval .. 15 = minimum interval.
  

•   Values 1 - 14 use a counter that decrements every cycle to generate a
  

•   timestamp on underflow. The reload value for the counter is 2 raised to
  

•   the power of timestamp interval - 1. If the value is 1 then the reload
  

•   value is 1, if the value is 11 then the reload value is 1024 etc.
  

 value = 11: 2^11-1 = 2047

Maybe add some parens?

Will do. I had them but I removed them because it was in a sentence so it made it look like a side note. I think I'll change from words to symbols:

The reload value for the counter is 2 ^ (interval - 1).

Thanks James