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Date: Wed, 1 May 2024 03:51:24 +0800
From: Leo Yan <leo.yan@linux.dev>
To: James Clark <james.clark@arm.com>
Cc: linux-perf-users@vger.kernel.org, coresight@lists.linaro.org,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@linaro.org>,
	John Garry <john.g.garry@oracle.com>, Will Deacon <will@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	"Liang, Kan" <kan.liang@linux.intel.com>,
	linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] perf cs-etm: Improve version detection and error
 reporting
Message-ID: <20240430195124.GD125@debian-dev>
References: <20240430133221.250811-1-james.clark@arm.com>
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In-Reply-To: <20240430133221.250811-1-james.clark@arm.com>

On Tue, Apr 30, 2024 at 02:32:21PM +0100, James Clark wrote:
> When the config validation functions are warning about ETMv3, they do it
> based on "not ETMv4". If the drivers aren't all loaded or the hardware
> doesn't support Coresight it will appear as "not ETMv4" and then Perf
> will print the error message "... not supported in ETMv3 ..." which is
> wrong and confusing.
> 
> cs_etm_is_etmv4() is also misnamed because it also returns true for
> ETE because ETE has a superset of the ETMv4 metadata files. Although
> this was always done in the correct order so it wasn't a bug.
> 
> Improve all this by making a single get version function which also
> handles not present as a separate case. Change the ETMv3 error message
> to only print when ETMv3 is detected, and add a new error message for
> the not present case.
> 
> Signed-off-by: James Clark <james.clark@arm.com>

Reviewed-by: Leo Yan <leo.yan@linux.dev>