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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 C9E0BC43142 for ; Tue, 31 Jul 2018 17:07:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80ABF20844 for ; Tue, 31 Jul 2018 17:07:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="gziQHP9C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80ABF20844 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.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 S1730028AbeGaSsu (ORCPT ); Tue, 31 Jul 2018 14:48:50 -0400 Received: from mail-it0-f67.google.com ([209.85.214.67]:38700 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727269AbeGaSsu (ORCPT ); Tue, 31 Jul 2018 14:48:50 -0400 Received: by mail-it0-f67.google.com with SMTP id v71-v6so5369480itb.3 for ; Tue, 31 Jul 2018 10:07:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=o73kjmIipNhpvnIs2UdndotC3Oh3Vq1qut2skvY3gD4=; b=gziQHP9CFyKdLds5MrND6GD5oYiaEmaLl8S6vfkNLSYblvJ4sYlRGL0pvO0EOKVrDl xi6uTdFWisk2OUV/SWjMQIhWQQr/iDi4uO5XlRGE5FoBnzoSM0eaQM7/ixRBPabNANRY r1CEOeQA+CsvJMpfCZKzuBR2z5Ju3GXN2K+n0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=o73kjmIipNhpvnIs2UdndotC3Oh3Vq1qut2skvY3gD4=; b=t27wkTmnOpITcVXJUOuqJYaQPupexOd3Giuy2KBFlJXjQYUjT1ovxZUX3yzbqU7eCv Ho0WCQValZgaihVpxxVlhNXJQwLOml0pHmAfSi2pC2QoQ1Bl+6rFJiP1ijkTDbRHrYTe wzKH6BVAX1GLoi/Bk2PoCQ4/+xu3JcTsmsi2saGNph4liWbsNqujZJltzAd8FI92XOn3 3B+qe+6jnpshSYIFGZ49bEBUY0FACzrR4XXXl/UOGNk6P3jWOifM5r/02vldqabS+uHi KBw9uP2I0uvjtpNXPbfbU2RpK/owj6M27XAUr5OoBpp4tEV/R1oA+HgL63cRNDjFUNDF 7oNg== X-Gm-Message-State: AOUpUlHBhKYHENhwOMVGADDT/N1FNO26YxHmmNWAQdSPlOjJjKMdTofk xBLP+7UKnzLkkzCCIOG/Z36WWg== X-Google-Smtp-Source: AAOMgpc8vXfW9EaiStOb5ZOivTUqND1BwdRaHNnRfEjNhmPuSEM2SaCMg+4E5QC8evOPuDpryNcYOg== X-Received: by 2002:a02:8c3c:: with SMTP id l57-v6mr21277427jak.57.1533056855542; Tue, 31 Jul 2018 10:07:35 -0700 (PDT) Received: from xps15 (S0106002369de4dac.cg.shawcable.net. [68.147.8.254]) by smtp.gmail.com with ESMTPSA id a79-v6sm1758607itc.33.2018.07.31.10.07.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 31 Jul 2018 10:07:34 -0700 (PDT) Date: Tue, 31 Jul 2018 11:07:31 -0600 From: Mathieu Poirier To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mike.leach@linaro.org, robert.walker@arm.com, coresight@lists.linaro.org Subject: Re: [PATCH v3 02/13] coresight: etb10: Fix handling of perf mode Message-ID: <20180731170731.GA11692@xps15> References: <1532609691-16863-1-git-send-email-suzuki.poulose@arm.com> <1532609691-16863-3-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1532609691-16863-3-git-send-email-suzuki.poulose@arm.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Thanks, Mathieu > > spin_lock_irqsave(&drvdata->spinlock, flags); > etb_enable_hw(drvdata); > -- > 2.7.4 >