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From:   Mathieu Poirier <mathieu.poirier@linaro.org>
Date:   Mon, 21 Oct 2019 11:42:21 -0600
Message-ID: <CANLsYkyvDKw4E7=+fsq7W41iS0P57Rau3fxJffrg8cEScyOOBw@mail.gmail.com>
Subject: Re: [PATCH] perf cs-etm: Fix definition of macro TO_CS_QUEUE_NR
To:     Leo Yan <leo.yan@linaro.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Coresight ML <coresight@lists.linaro.org>
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On Mon, 21 Oct 2019 at 01:48, Leo Yan <leo.yan@linaro.org> wrote:
>
> Macro TO_CS_QUEUE_NR definition has a typo, which uses 'trace_id_chan'
> as its parameter, this doesn't match with its definition body which uses
> 'trace_chan_id'.  So renames the parameter to 'trace_chan_id'.
>
> It's luck to have a local variable 'trace_chan_id' in the function
> cs_etm__setup_queue(), even we wrongly define the macro TO_CS_QUEUE_NR,
> the local variable 'trace_chan_id' is used rather than the macro's
> parameter 'trace_id_chan'; so the compiler doesn't complain for this
> before.
>
> After renaming the parameter, it leads to a compiling error due
> cs_etm__setup_queue() has no variable 'trace_id_chan'.  This patch uses
> the variable 'trace_chan_id' for the macro so that fixes the compiling
> error.
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
>  tools/perf/util/cs-etm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index 4ba0f871f086..f5f855fff412 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -110,7 +110,7 @@ static int cs_etm__decode_data_block(struct cs_etm_queue *etmq);
>   * encode the etm queue number as the upper 16 bit and the channel as
>   * the lower 16 bit.
>   */
> -#define TO_CS_QUEUE_NR(queue_nr, trace_id_chan)        \
> +#define TO_CS_QUEUE_NR(queue_nr, trace_chan_id)        \
>                       (queue_nr << 16 | trace_chan_id)
>  #define TO_QUEUE_NR(cs_queue_nr) (cs_queue_nr >> 16)
>  #define TO_TRACE_CHAN_ID(cs_queue_nr) (cs_queue_nr & 0x0000ffff)
> @@ -819,7 +819,7 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm,
>          * Note that packets decoded above are still in the traceID's packet
>          * queue and will be processed in cs_etm__process_queues().
>          */
> -       cs_queue_nr = TO_CS_QUEUE_NR(queue_nr, trace_id_chan);
> +       cs_queue_nr = TO_CS_QUEUE_NR(queue_nr, trace_chan_id);
>         ret = auxtrace_heap__add(&etm->heap, cs_queue_nr, timestamp);
>  out:
>         return ret;

Really good catch - Arnaldo please consider.

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> --
> 2.17.1
>