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=-12.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 1BC1BC433E1 for ; Fri, 21 Aug 2020 03:48:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB3CB20855 for ; Fri, 21 Aug 2020 03:48:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="OKwkvFPJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727807AbgHUDsv (ORCPT ); Thu, 20 Aug 2020 23:48:51 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:30017 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727074AbgHUDsu (ORCPT ); Thu, 20 Aug 2020 23:48:50 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1597981729; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=NR00TQF2Q5NvhlGOYyoA7Yqsrftx/gbgVvITw5cWsW0=; b=OKwkvFPJI/x/jg7U6tvTCqx86hzi2driJIUzfb7LgukUFIr4koLEOy8K7fEY/0nWxnnt2OLS PzUqp7lBvQOgrkGlQs7qyPKtsN+LTBpxoz8RJXiOfpwTF/Lr/2qeMU7RB35+yk827XMa4DdW KX72voDHimZecAXUgwed/2DtEcY= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-west-2.postgun.com with SMTP id 5f3f44130dab4fdee212e817 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 21 Aug 2020 03:48:35 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8B504C433A0; Fri, 21 Aug 2020 03:48:35 +0000 (UTC) Received: from tingweiz-gv.qualcomm.com (unknown [180.166.53.21]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: tingwei) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4C208C433C6; Fri, 21 Aug 2020 03:48:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4C208C433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=tingwei@codeaurora.org From: Tingwei Zhang To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin , Mike Leach Cc: Tingwei Zhang , Greg Kroah-Hartman , Leo Yan , Randy Dunlap , Russell King , Kim Phillips , Mian Yousaf Kaukab , tsoni@codeaurora.org, Sai Prakash Ranjan , Mao Jinlong , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v10 20/24] coresight: cti: increase reference count when enabling cti Date: Fri, 21 Aug 2020 11:44:41 +0800 Message-Id: <20200821034445.967-21-tingwei@codeaurora.org> X-Mailer: git-send-email 2.20.0 In-Reply-To: <20200821034445.967-1-tingwei@codeaurora.org> References: <20200821034445.967-1-tingwei@codeaurora.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CTI device is enabled when associated coresight device is enabled. Increase the module and device reference count for CTI device when it's enabled. This can prevent CTI device be removed or module be unloaded when CTI device is enabled by an active trace session. Signed-off-by: Mike Leach Signed-off-by: Tingwei Zhang --- drivers/hwtracing/coresight/coresight.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index d354fd57474e..6c9f6930b8b8 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -241,19 +241,30 @@ coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable) { int ect_ret = 0; struct coresight_device *ect_csdev = csdev->ect_dev; + struct module *mod; if (!ect_csdev) return 0; if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable)) return 0; + mod = ect_csdev->dev.parent->driver->owner; if (enable) { - ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); - if (!ect_ret) - csdev->ect_enabled = true; + if (try_module_get(mod)) { + ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); + if (ect_ret) { + module_put(mod); + } else { + get_device(ect_csdev->dev.parent); + csdev->ect_enabled = true; + } + } else + ect_ret = -ENODEV; } else { if (csdev->ect_enabled) { ect_ret = ect_ops(ect_csdev)->disable(ect_csdev); + put_device(ect_csdev->dev.parent); + module_put(mod); csdev->ect_enabled = false; } } -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project