Re: [PATCH v4 8/8] perf hisi-ptt: Pass pattern version to decoder for compatibility

[sashiko-bot@kernel.org]

> On the recording side, walk the evlist in hisi_ptt_info_fill() to find
> the hisi_ptt event, read out the pattern bits from its config, and
> forward the pattern version to the decoder through
> auxtrace_info->priv[1] as HISI_PTT_PATTERN_LEGACY or HISI_PTT_PATTERN_V1.
> 
> On the decoding side, store the pattern version in struct hisi_ptt and
> propagate it to struct hisi_ptt_pkt_buf. The printers of Header DW2
> and DW3 check the version: HISI_PTT_PATTERN_V1 keeps the field-level
> parsing introduced by the previous patches, while HISI_PTT_PATTERN_LEGACY
> falls back to printing only the raw "Header DW2/DW3" label so legacy
> traces remain decodable with the new tool.
> 
> The auxtrace priv size grows from one u64 to two. Use
> HISI_PTT_AUXTRACE_PRIV_SIZE_LEGACY for the minimum header size check
> and detect the actual priv_size at runtime to pick the pattern version.
> For trace data recorded by an older tracer that does not support the
> `pattern` parameter (no priv[1] in the header), the decoder defaults
> to legacy mode (HISI_PTT_PATTERN_LEGACY) so the new tool keeps parsing
> old traces correctly.
> 
> The hisi_ptt_pkt_size array is moved out of the shared header into
> static definitions in the two .c files that consume it to avoid
> multiple definitions.
> 
> Reviewed-by: Yushan Wang <wangyushan12@huawei.com>
> Signed-off-by: Sizhe Liu <liusizhe5@huawei.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260908140509.2485649-1-liusizhe5@huawei.com?part=8