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Subject: Re: [PATCH v3 2/2] coresight: Update comments for removing
 cs_etm_find_snapshot()
To:     Leo Yan <leo.yan@linaro.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Mike Leach <mike.leach@linaro.org>,
        James Clark <james.clark@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <20210905131237.1035322-1-leo.yan@linaro.org>
 <20210905131237.1035322-3-leo.yan@linaro.org>
From:   Suzuki K Poulose <suzuki.poulose@arm.com>
Message-ID: <4db83b64-445d-2a04-a130-fd95f9157702@arm.com>
Date:   Mon, 6 Sep 2021 10:51:02 +0100
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Hi Leo


On 05/09/2021 14:12, Leo Yan wrote:
> Commit 2f01c200d440 ("perf cs-etm: Remove callback cs_etm_find_snapshot()")
> has removed the function cs_etm_find_snapshot() from the perf tool in the
> user space, now CoreSight trace directly uses the perf common function
> __auxtrace_mmap__read() to calcualte the head and size for AUX trace data
> in snapshot mode.
> 
> Updates the comments in drivers to reflect the changes.

As such I would avoid referencing "userspace" function names in the
kernel driver. Please could we remove it or make it generic ?

Also, remember, perf is not the only userspace tool driving the kernel
perf.

Cheers
Suzuki

> 
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
>   drivers/hwtracing/coresight/coresight-etb10.c   | 2 +-
>   drivers/hwtracing/coresight/coresight-tmc-etf.c | 2 +-
>   drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +-
>   3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index f775cbee12b8..1cdb627d6c38 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -557,7 +557,7 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev,
>   
>   	/*
>   	 * In snapshot mode we simply increment the head by the number of byte
> -	 * that were written.  User space function  cs_etm_find_snapshot() will
> +	 * that were written.  User space function __auxtrace_mmap__read() will
>   	 * figure out how many bytes to get from the AUX buffer based on the
>   	 * position of the head.
>   	 */
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index cd0fb7bfba68..a895931a2766 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -546,7 +546,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev,
>   
>   	/*
>   	 * In snapshot mode we simply increment the head by the number of byte
> -	 * that were written.  User space function  cs_etm_find_snapshot() will
> +	 * that were written.  User space function __auxtrace_mmap__read() will
>   	 * figure out how many bytes to get from the AUX buffer based on the
>   	 * position of the head.
>   	 */
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index d23c7690f29a..941abb70b827 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -1573,7 +1573,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
>   
>   	/*
>   	 * In snapshot mode we simply increment the head by the number of byte
> -	 * that were written.  User space function  cs_etm_find_snapshot() will
> +	 * that were written.  User space function __auxtrace_mmap__read() will
>   	 * figure out how many bytes to get from the AUX buffer based on the
>   	 * position of the head.
>   	 */
>