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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 27DBDC28B20 for ; Wed, 2 Apr 2025 13:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=I+53JZL1E+oZIZ7NO5SZiRrBTAjs8/1VFvBN/OXohjk=; b=42YHyd0B0dO2Jvm/sosoD8IFKr VWALoC3+FdTLwvQMnHKNbQXOKN2TC9uJpX8jUn/6Au34TRi5MWSiP6OJrkFtmQzTkq70ABnS0YsTm O/kww7D9Dr76CWeNoTq2QB2ZUs/E9wHyw35Mkmpx2p0kUBUZ6otVoZ47aXqsrxd4GOAhqM/BIhNfm dEc1PQOn9r66f/s89yu/yp4E1zXFMm1iq2wyVkg9zPggkDP6bqW4d3lOVTHtO2po5bgfssW2P2CFH jjGuVlQayWAxYMP3MKNUEmZj9CrQBl3llpYSx/iEsFpmPPCqpgjqENlYCzoyp4E3PRqtFVygygmYr 0kJDzqxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzxks-00000006Bit-0WW1; Wed, 02 Apr 2025 13:03:42 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzxj5-00000006B4N-3YZJ for linux-arm-kernel@lists.infradead.org; Wed, 02 Apr 2025 13:01:53 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 16EF7106F; Wed, 2 Apr 2025 06:01:54 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A5F983F694; Wed, 2 Apr 2025 06:01:50 -0700 (PDT) Date: Wed, 2 Apr 2025 14:01:45 +0100 From: Leo Yan To: Yabin Cui Cc: Suzuki K Poulose , Mike Leach , James Clark , Alexander Shishkin , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] coresight: catu: Introduce refcount and spinlock for enabling/disabling Message-ID: <20250402130145.GI115840@e132581.arm.com> References: <20250402011832.2970072-1-yabinc@google.com> <20250402011832.2970072-2-yabinc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250402_060151_928781_6D844F3F X-CRM114-Status: GOOD ( 13.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Yabin, On Tue, Apr 01, 2025 at 06:21:59PM -0700, Yabin Cui wrote: [...] > > @@ -486,12 +491,17 @@ static int catu_disable_hw(struct catu_drvdata *drvdata) > > > > static int catu_disable(struct coresight_device *csdev, void *__unused) > > { > > - int rc; > > + int rc = 0; > > struct catu_drvdata *catu_drvdata = csdev_to_catu_drvdata(csdev); > > + guard(raw_spinlock_irqsave)(&catu_drvdata->spinlock); > > > > - CS_UNLOCK(catu_drvdata->base); > > - rc = catu_disable_hw(catu_drvdata); > > - CS_LOCK(catu_drvdata->base); > > + if (--csdev->refcnt == 0) { > > + CS_UNLOCK(catu_drvdata->base); > > + rc = catu_disable_hw(catu_drvdata); > > + CS_LOCK(catu_drvdata->base); > > + } else { > > + rc = -EBUSY; This is not an error if the decremented reference counter is not zero. It should return 0. Otherwise, the change looks good to me. Thanks, Leo