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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 B9395C43387 for ; Sat, 12 Jan 2019 12:51:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 806762086C for ; Sat, 12 Jan 2019 12:51:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="efBTxDQr"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="Ti5QamKz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725863AbfALMvC (ORCPT ); Sat, 12 Jan 2019 07:51:02 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:52430 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725834AbfALMvC (ORCPT ); Sat, 12 Jan 2019 07:51:02 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 97623608A5; Sat, 12 Jan 2019 12:51:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1547297461; bh=vc95Z/tMlWNdjowrwCwRgmlvYWxkp4Ha9JVSJUZtmRw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=efBTxDQrAUC6i3csoz7boD3nLvf3rJvOQk+L9BmwSRurQcswXvLaCU9ABEojoc6cu /TTk3HzC4nZmNHTTaEZ0YZC2vW2HpgWDiJqO/xedrNi9UxRoxCsfA8cAliU80/1syv kzcuBdngmV6a+1Nfn/8NQfK410f7zr/A7uOMgoCk= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id CF28B6087F; Sat, 12 Jan 2019 12:51:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1547297460; bh=vc95Z/tMlWNdjowrwCwRgmlvYWxkp4Ha9JVSJUZtmRw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Ti5QamKzeZ1n7mzWuR9OIUfBx8DLh82A/ne0E++ehrYuFCH79PMffGcpZ3jWdkNVP RZ5V/Gy4WInJZVuHnYZfC7K2PbR+Z0Rb4SBdWbS8LaU3wNViMzbhO+d5OUW0cuCDId 7ZPAn+2WOJ5j/vUdQLrt9UEsH9BCa8QHk474Sk4A= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Sat, 12 Jan 2019 18:21:00 +0530 From: saiprakash.ranjan@codeaurora.org To: Mathieu Poirier Cc: Rob Herring , Suzuki K Poulose , Leo Yan , Alexander Shishkin , Andy Gross , David Brown , devicetree@vger.kernel.org, Mark Rutland , Rajendra Nayak , Vivek Gautam , Sibi Sankar , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-msm-owner@vger.kernel.org Subject: Re: [PATCH 1/3] arm64: dts: qcom: sdm845: Add Coresight support In-Reply-To: <20190111184643.GA22691@xps15> References: <20190111184643.GA22691@xps15> Message-ID: <81172d85ed7782e0db561fcf96a82d46@codeaurora.org> X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mathieu, >> + >> + etm@7040000 { >> + compatible = "arm,coresight-etm4x", "arm,primecell"; >> + arm,primecell-periphid = <0x000bb95d>; > > I'm a little curious as to why you need to bypass the normal AMBA bus > discovery > method by forcing the peripheral ID. Tracers don't show up the way > other > coresight devices do at boot time? > Yes on some Qcom SoC's like SDM845 and also on some previous ones, for ETM(only) amba bus discovery method fails because of wrong pid read from the registers. So we have to force this primecell peripheral ids to probe etm. - Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation