From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A28DC43470 for ; Mon, 10 May 2021 13:15:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 303436128D for ; Mon, 10 May 2021 13:15:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234807AbhEJNO7 (ORCPT ); Mon, 10 May 2021 09:14:59 -0400 Received: from foss.arm.com ([217.140.110.172]:58090 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351653AbhEJNMX (ORCPT ); Mon, 10 May 2021 09:12:23 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 364EC1688; Mon, 10 May 2021 06:11:18 -0700 (PDT) Received: from [10.57.47.14] (unknown [10.57.47.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5AE143F73B; Mon, 10 May 2021 06:11:16 -0700 (PDT) Subject: Re: [PATCH v1 0/3] coresight: Support for building more coresight paths To: Tao Zhang , Mathieu Poirier , Alexander Shishkin Cc: Mike Leach , Leo Yan , Greg Kroah-Hartman , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tingwei Zhang , Mao Jinlong , Yuanfang Zhang References: <1620644727-29279-1-git-send-email-taozha@codeaurora.org> From: Suzuki K Poulose Message-ID: <070d1c13-2b3e-2dfb-f51b-9d40f1b45a03@arm.com> Date: Mon, 10 May 2021 14:10:52 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <1620644727-29279-1-git-send-email-taozha@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tao On 10/05/2021 12:05, Tao Zhang wrote: > We are trying to achieve more types of Coresight source devices. > For example, we have a type of coresight source devic named TPDM. > In the process of using, sometimes mulitiple TPDMs need to be > connected to the different input ports on the same funnel. > Meanwhile, these TPDMs also need to output from different > ports on the funnel. > But, at present the Coresight driver assumes > a) Only support Coresight source type ETM, ETR and ETF Did you mean ETM and STM here ? ETR & ETF are not source types, rather they are SINK. > b) Funnels only support mulitiple inputs and one output > Which doesn't help to add the above feature for our new Coresight > source device TPDM. So, in order to accommodate the new device, > we develop the following patches. Where is the TPDM driver ? Could you give us a rough idea of the behavior in terms of the input / output ? > a) Add support more types of Coresight source devices. Which ones ? where is the code ? > b) Add support for multiple output ports on funnel and the output > ports could be selected by Corsight source. Does the "TPDM" require programming to switch these output or are these "static" ? Is this something that can be avoided by having a "fake" static-replicator in the path ? e.g, TPDM ________________________________________________ In0 | | -> Out0 In1 | Static-Funnel -> Static-Replicator | -> Out1 In2 | | -> Out2 ________________________________________________ Is this something that can be solved ? Again, please give a brief description of the TPDM device and the driver code in the series to give us a complete picture of what you are trying to do. Reviewing some changes without having the full picture is not going to be helpful. Suzuki