[PATCH v1 0/3] coresight: Fix for snapshot mode

Suzuki K Poulose suzuki.poulose at arm.com
Thu Jun 10 09:04:40 PDT 2021


Hi Denis

On 10/06/2021 07:43, Denis Nikitin wrote:
> Hi Leo,
> 
> On Fri, May 28, 2021 at 9:16 AM Leo Yan <leo.yan at linaro.org> 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.

Are you able to confirm if the patch 3 alone fixes the above issue ?
I am not convinced that Patch 1 is necessary.

Suzuki



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