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=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED autolearn=ham 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 CC610C67871 for ; Sat, 6 Oct 2018 16:38:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E5952084D for ; Sat, 6 Oct 2018 16:38:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="spYkkGUF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E5952084D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727802AbeJFXmY (ORCPT ); Sat, 6 Oct 2018 19:42:24 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:38574 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725266AbeJFXmY (ORCPT ); Sat, 6 Oct 2018 19:42:24 -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=9L3PusQtZHJPoFDTUa2lzYEr5j16up4N+qr+FN1KZTc=; b=spYkkGUFNhqGaIwUATrsKk55M FE1sYz9cg/XJvMIblDXcG3BffB1NDauyC2Gf8jHIk/C3YbcNajiwhHXwBFYn9t9RfpF0Qq1Y13J8E 9DvItwm4Ag2vxLm8ub7oMfA/6YJQQbP6ABHxGeAxTxapbeN2Vv1R/9MGuWyslBBc9YsnrC13pV/vP mauuatT4o3/DZZaV/GETytLw9+JM7+QGwPULgOxpaSZoQ/SdqFYb5coCGttEmUD4lvzW1TTs82BnZ y9iRqfQWWc+KBzYjq76ObMfpZe/YeL8A8pLP2v3N9OgAR4YD9IyOU6TLVmKODJf3WJAVZmBrxAK0V vOi2oUd/A==; 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 1g8pax-0000He-L9; Sat, 06 Oct 2018 16:38:23 +0000 Subject: Re: [GIT PULL 11/16] stm class: Document the MIPI SyS-T protocol usage To: Alexander Shishkin , Greg Kroah-Hartman Cc: Mathieu Poirier , linux-kernel@vger.kernel.org References: <20181005124306.54870-1-alexander.shishkin@linux.intel.com> <20181005124306.54870-12-alexander.shishkin@linux.intel.com> From: Randy Dunlap Message-ID: <5e7d8200-d357-4105-b00a-3ca36d375aac@infradead.org> Date: Sat, 6 Oct 2018 09:38:22 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20181005124306.54870-12-alexander.shishkin@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, one small typo/spello below... On 10/5/18 5:43 AM, Alexander Shishkin wrote: > Add a document describing MIPI SyS-T protocol driver usage. > > Signed-off-by: Alexander Shishkin > Tested-by: Mathieu Poirier > --- > Documentation/trace/sys-t.rst | 62 +++++++++++++++++++++++++++++++++++ > 1 file changed, 62 insertions(+) > create mode 100644 Documentation/trace/sys-t.rst > > diff --git a/Documentation/trace/sys-t.rst b/Documentation/trace/sys-t.rst > new file mode 100644 > index 000000000000..3d8eb92735e9 > --- /dev/null > +++ b/Documentation/trace/sys-t.rst > @@ -0,0 +1,62 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +=================== > +MIPI SyS-T over STP > +=================== > + > +The MIPI SyS-T protocol driver can be used with STM class devices to > +generate standardized trace stream. Aside from being a standard, it > +provides better trace source identification and timestamp correlation. > + > +In order to use the MIPI SyS-T protocol driver with your STM device, > +first, you'll need CONFIG_STM_PROTO_SYS_T. > + > +Now, you can select which protocol driver you want to use when you create > +a policy for your STM device, by specifying it in the policy name: > + > +# mkdir /config/stp-policy/dummy_stm.0:p_sys-t.my-policy/ > + > +In other words, the policy name format is extended like this: > + > + :. > + > +With Intel TH, therefore it can look like "0-sth:p_sys-t.my-policy". > + > +If the protocol name is omitted, the STM class will chose whichever s/chose/choose/ > +protocol driver was loaded first. > + > +You can also double check that everything is working as expected by > + > +# cat /config/stp-policy/dummy_stm.0:p_sys-t.my-policy/protocol > +p_sys-t > + > +Now, with the MIPI SyS-T protocol driver, each policy node in the > +configfs gets a few additional attributes, which determine per-source > +parameters specific to the protocol: > + > +# mkdir /config/stp-policy/dummy_stm.0:p_sys-t.my-policy/default > +# ls /config/stp-policy/dummy_stm.0:p_sys-t.my-policy/default > +channels > +clocksync_interval > +do_len > +masters > +ts_interval > +uuid > + > +The most important one here is the "uuid", which determines the UUID > +that will be used to tag all data coming from this source. It is > +automatically generated when a new node is created, but it is likely > +that you would want to change it. > + > +do_len switches on/off the additional "payload length" field in the > +MIPI SyS-T message header. It is off by default as the STP already > +marks message boundaries. > + > +ts_interval and clocksync_interval determine how much time in milliseconds > +can pass before we need to include a protocol (not transport, aka STP) > +timestamp in a message header or send a CLOCKSYNC packet, respectively. > + > +See Documentation/ABI/testing/configfs-stp-policy-p_sys-t for more > +details. > + > +* [1] https://www.mipi.org/specifications/sys-t > -- ~Randy