From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.6 required=5.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 849C27D048 for ; Mon, 14 May 2018 21:03:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752380AbeENVD3 (ORCPT ); Mon, 14 May 2018 17:03:29 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56006 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752238AbeENVDZ (ORCPT ); Mon, 14 May 2018 17:03:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To: Subject:Sender:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=hdMCU9GjrUP2DOzINR27cve6k8nPt6FKPeNwqgSC1xs=; b=fzIvYVHYBMyyjd7r3CEtpamTT uChcNMxKdpdeJk7munbxf9Of7Yqe2ebMM3FP6E+VUQLP49Y3eBsJWimb9QMI1WT2IJseiRgthksca v2cyy0sjleJj8jEExDBLfRN8wkg9mm/e4dN6zcp+vBLdzxI0y9YUp1+wK3mvaJS0PFJyYv17yNr4R m3SfLcqaJ8gzogoSOo3K5JT3FiAK3cSiwqto7G6WIPJFDhivCn7Q1ZGq7/niGduFD3J5oCrtUUT2g dGwJsa+bDJkAkFlLxjkh7F0BaozAyIfgo1I+WGLnLH4ecYWMidjC0i6Uw4mpnhYyCPNmf64aZp6e+ W26rCoy5g==; Received: from static-50-53-52-16.bvtn.or.frontiernet.net ([50.53.52.16] helo=midway.dunlab) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fIKcn-0001eu-FP; Mon, 14 May 2018 21:03:17 +0000 Subject: Re: [PATCH v3] coresight: documentation: update sysfs section To: Kim Phillips , Mathieu Poirier Cc: Jonathan Corbet , linux-arm-kernel , "open list:DOCUMENTATION" , linux-kernel@vger.kernel.org References: <20180507172915.c032cd71c07b1849bf419a5f@arm.com> <20180514121959.a9a3d2fb3d3d270849ffbc39@arm.com> <20180514141800.f1be30ce9d1f6ae20ca2d04c@arm.com> From: Randy Dunlap Message-ID: <8bcf5490-aeea-e531-fc2d-e8aff8a62dbc@infradead.org> Date: Mon, 14 May 2018 14:03:16 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180514141800.f1be30ce9d1f6ae20ca2d04c@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 05/14/2018 12:18 PM, Kim Phillips wrote: > - Align and show updated ls devices output from the TC2, based on > current driver > > - Provide an example from an ETMv4 based system (Juno) > > - Reflect changes to the way the RAM write pointer is accessed since > it got changed in commit 7d83d17795ef ("coresight: tmc: adding sysFS > management entries"). > > Cc: Mathieu Poirier > Cc: Randy Dunlap > Cc: Jonathan Corbet > Signed-off-by: Kim Phillips FWIW: Acked-by: Randy Dunlap Thanks. > --- > v3: address Randy Dunlap's showns->shown, corrected - and + line merging > v2: address Mathieu's comment about clarifying the sinks on the Juno > vs. TC2 platforms. > > Documentation/trace/coresight.txt | 43 +++++++++++++++++++------------ > 1 file changed, 26 insertions(+), 17 deletions(-) > > diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.txt > index 6f0120c3a4f1..15d2a0f1e1b8 100644 > --- a/Documentation/trace/coresight.txt > +++ b/Documentation/trace/coresight.txt > @@ -141,13 +141,25 @@ register the device with the core framework. The unregister function takes > a reference to a "struct coresight_device", obtained at registration time. > > If everything goes well during the registration process the new devices will > -show up under /sys/bus/coresight/devices, as showns here for a TC2 platform: > +show up under /sys/bus/coresight/devices, as shown here for a TC2 platform: > > root:~# ls /sys/bus/coresight/devices/ > -replicator 20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm > -20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm > +20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm replicator > +20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm > root:~# > > +and here for a Juno platform: > + > +root@juno:~# ls /sys/bus/coresight/devices/ > +20010000.etf 20120000.replicator 22040000.etm 230c0000.funnel > +20030000.tpiu 20130000.funnel 220c0000.funnel 23140000.etm > +20040000.funnel 20140000.etf 22140000.etm 23240000.etm > +20070000.etr 20150000.funnel 23040000.etm 23340000.etm > +root@juno:~# > + > +Note that on Juno users can select the ETF, ETR and TPIU as a sink target while > +on TC2, the ETB and TPIU can be selected. > + > The functions take a "struct coresight_device", which looks like this: > > struct coresight_desc { > @@ -193,16 +205,16 @@ the information carried in "THIS_MODULE". > How to use the tracer modules > ----------------------------- > > -Before trace collection can start, a coresight sink needs to be identify. > +Before trace collection can start, a coresight sink needs to be identified. > There is no limit on the amount of sinks (nor sources) that can be enabled at > any given moment. As a generic operation, all device pertaining to the sink > class will have an "active" entry in sysfs: > > root:/sys/bus/coresight/devices# ls > -replicator 20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm > -20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm > +20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm replicator > +20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm > root:/sys/bus/coresight/devices# ls 20010000.etb > -enable_sink status trigger_cntr > +enable_sink mgmt power subsystem trigger_cntr uevent > root:/sys/bus/coresight/devices# echo 1 > 20010000.etb/enable_sink > root:/sys/bus/coresight/devices# cat 20010000.etb/enable_sink > 1 > @@ -216,16 +228,13 @@ trigger a trace capture: > root:/sys/bus/coresight/devices# echo 1 > 2201c000.ptm/enable_source > root:/sys/bus/coresight/devices# cat 2201c000.ptm/enable_source > 1 > -root:/sys/bus/coresight/devices# cat 20010000.etb/status > -Depth: 0x2000 > -Status: 0x1 > -RAM read ptr: 0x0 > -RAM wrt ptr: 0x19d3 <----- The write pointer is moving > -Trigger cnt: 0x0 > -Control: 0x1 > -Flush status: 0x0 > -Flush ctrl: 0x2001 > -root:/sys/bus/coresight/devices# > + > +Observe the write pointer moving: > + > +root:/sys/bus/coresight/devices# cat 20010000.etb/mgmt/rwp > +0x1a8 > +root:/sys/bus/coresight/devices# cat 20010000.etb/mgmt/rwp > +0x19a6 > > Trace collection is stopped the same way: > > -- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html