From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: leo.yan@linaro.org, mathieu.poirier@linaro.org,
robh+dt@kernel.org, mark.rutland@arm.com,
alexander.shishkin@linux.intel.com,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, coresight@lists.linaro.org,
shiwanglai@hisilicon.com
Subject: Re: [PATCH v3 2/2] coresight: funnel: Support static funnel
Date: Thu, 28 Mar 2019 19:26:16 +0000 [thread overview]
Message-ID: <799f3f27-6a20-836e-b699-252ebb8e2fdf@arm.com> (raw)
In-Reply-To: <20190328023509.22242-3-leo.yan@linaro.org>
On 03/28/2019 02:35 AM, Leo Yan wrote:
> Since CoreSight hardware topology can use a 'hidden' funnel in the
> trace data path, this kind funnel doesn't have register for accessing
> and is used by default from hardware design perspective. Below is an
> example for related hardware topology:
>
> +------+ +------+
> | cpu0 |->| ETM |-\
> +------+ +------+ \-> +--------+ +-----+
> ...... | Funnel |->| ETF |-\ Hidden funnel
> +------+ +------+ /-> +--------+ +-----+ \ |
> | cpu3 |->| ETM |-/ \ V
> +------+ +------+ \-> +--------+
> | Funnel |-> ...
> +------+ +------+ /-> +--------+
> | cpu4 |->| ETM |-\ /
> +------+ +------+ \-> +--------+ +-----+ /
> ...... | Funnel |->| ETF |-/
> +------+ +------+ /-> +--------+ +-----+
> | cpu7 |->| ETM |-/
> +------+ +------+
>
> The CoreSight funnel driver only supports dynamic funnel with
> registration register resource, thus it cannot support for the static
> funnel case and it's impossible to create trace data path for this case.
>
> This patch is to extend CoreSight funnel driver to support both for
> static funnel and dynamic funnel. For the dynamic funnel it reuses the
> code existed in the driver, for static funnel the driver will support
> device probe if without providing register resource and the driver skips
> registers accessing when detect the register base is NULL.
>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Wanglai Shi <shiwanglai@hisilicon.com>
> Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
prev parent reply other threads:[~2019-03-28 19:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-28 2:35 [PATCH v3 0/2] CoreSight: Support static funnel Leo Yan
2019-03-28 2:35 ` [PATCH v3 1/2] dt-bindings: arm: coresight: " Leo Yan
2019-03-28 19:06 ` Rob Herring
2019-03-28 19:24 ` Suzuki K Poulose
2019-03-29 0:21 ` Leo Yan
2019-03-28 2:35 ` [PATCH v3 2/2] coresight: funnel: " Leo Yan
2019-03-28 19:26 ` Suzuki K Poulose [this message]
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