Hi Leo,

On Fri, May 28, 2021 at 9:16 AM Leo Yan [off-list ref] wrote:

This patch series is to correct the pointer usages for the snapshot
mode.

Patch 01 allows the AUX trace in the free run mode and only syncs the
AUX ring buffer when taking snapshot.

Patch 02 is to polish code, it removes the redundant header maintained
in tmc-etr driver and directly uses pointer perf_output_handle::head.

Patch 03 removes the callback cs_etm_find_snapshot() which wrongly
calculates the buffer headers; we can simply use the perf's common
function __auxtrace_mmap__read() for headers calculation.

This patch can be cleanly applied on the mainline kernel with:

  commit 97e5bf604b7a ("Merge branch 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu")

And it has been tested on Arm64 Juno board.

I have verified the patches on Chrome OS Trogdor device.
They fixed the problem discussed in
https://lists.linaro.org/pipermail/coresight/2021-May/006411.html.

Tested-by: Denis Nikitin <redacted>

Thanks,
Denis

Leo Yan (3):
  coresight: etm-perf: Correct buffer syncing for snapshot
  coresight: tmc-etr: Use perf_output_handle::head for AUX ring buffer
  perf cs-etm: Remove callback cs_etm_find_snapshot()

 .../hwtracing/coresight/coresight-etm-perf.c  |  30 +++-
 .../hwtracing/coresight/coresight-etm-perf.h  |   2 +
 .../hwtracing/coresight/coresight-tmc-etr.c   |  10 +-
 tools/perf/arch/arm/util/cs-etm.c             | 133 ------------------
 4 files changed, 32 insertions(+), 143 deletions(-)

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2.25.1