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=-1.0 required=3.0 tests=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 10098C43142 for ; Tue, 31 Jul 2018 21:32:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A666920857 for ; Tue, 31 Jul 2018 21:32:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A666920857 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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 S1732558AbeGaXOW (ORCPT ); Tue, 31 Jul 2018 19:14:22 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:60752 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727076AbeGaXOV (ORCPT ); Tue, 31 Jul 2018 19:14:21 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 221A780D; Tue, 31 Jul 2018 14:32:04 -0700 (PDT) Received: from [10.37.10.25] (unknown [10.37.10.25]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3D863F5BA; Tue, 31 Jul 2018 14:32:02 -0700 (PDT) Subject: Re: [PATCH v3 02/13] coresight: etb10: Fix handling of perf mode To: Mathieu Poirier Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mike.leach@linaro.org, robert.walker@arm.com, coresight@lists.linaro.org References: <1532609691-16863-1-git-send-email-suzuki.poulose@arm.com> <1532609691-16863-3-git-send-email-suzuki.poulose@arm.com> <20180731170731.GA11692@xps15> From: Suzuki K Poulose Message-ID: <7b311596-025a-f4f4-1859-6f3531258b75@arm.com> Date: Tue, 31 Jul 2018 22:32:39 +0100 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: <20180731170731.GA11692@xps15> Content-Type: text/plain; charset=utf-8; format=flowed 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 On 07/31/2018 06:07 PM, Mathieu Poirier wrote: > Hello, > > On Thu, Jul 26, 2018 at 01:54:40PM +0100, Suzuki K Poulose wrote: >> If the ETB is already enabled in sysfs mode, the ETB reports >> success even if a perf mode is requested. Fix this by checking >> the requested mode. >> >> Cc: Mathieu Poirier >> Signed-off-by: Suzuki K Poulose >> --- >> drivers/hwtracing/coresight/coresight-etb10.c | 8 ++++++-- >> 1 file changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c >> index 306119e..e5808fd 100644 >> --- a/drivers/hwtracing/coresight/coresight-etb10.c >> +++ b/drivers/hwtracing/coresight/coresight-etb10.c >> @@ -148,8 +148,12 @@ static int etb_enable(struct coresight_device *csdev, u32 mode) >> return -EBUSY; >> >> /* Nothing to do, the tracer is already enabled. */ >> - if (val == CS_MODE_SYSFS) >> - goto out; >> + if (val == CS_MODE_SYSFS) { >> + if (mode == CS_MODE_SYSFS) >> + goto out; >> + else >> + return -EBUSY; >> + } > > How about: > > if (val == CS_MODE_PERF) > return -EBUSY; > > + /* Don't let perf disturb sysFS sessions */ > + if (val == CS_MODE_SYSFS && mode = CS_MODE_PERF) > + return -EBUSY; > + > /* Nothing to do, the tracer is already enabled. */ > if (val == CS_MODE_SYSFS) > goto out; > > > I just find it more readable that way. Sure, thats fine by me. Cheers Suzuki