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=-8.7 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 92EDCC65BAF for ; Sun, 9 Dec 2018 19:52:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5128420672 for ; Sun, 9 Dec 2018 19:52:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kemnade.info header.i=@kemnade.info header.b="AHH1UqYQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5128420672 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kemnade.info 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 S1726396AbeLITwF (ORCPT ); Sun, 9 Dec 2018 14:52:05 -0500 Received: from mail.andi.de1.cc ([85.214.239.24]:40568 "EHLO h2641619.stratoserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726377AbeLITwB (ORCPT ); Sun, 9 Dec 2018 14:52:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kemnade.info; s=20180802; h=References:In-Reply-To:Message-Id:Date:Subject: Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ut/8c9YFJfU+elcZAGNLhrWmsHsQosbLOl9ws4x5Z4c=; b=AHH1UqYQXMFO8dkB0WARvglqS iMja9k2bpIddx98XeNihmTlL1A8/g0GY8Zzu+pctGkbWYPn8d9/IAf8IcNhk9mNyAEVTMDUhHOJOD IKrzJ9nXONEUYhnj910x5MgBDQLqqzqZ7xWOt34a4f7wTzZUQUUAHzopGTN51gwmuD4j4=; Received: from p200300ccfbead7001a3da2fffebfd33a.dip0.t-ipconnect.de ([2003:cc:fbea:d700:1a3d:a2ff:febf:d33a] helo=aktux) by h2641619.stratoserver.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW57M-0008JA-Vr; Sun, 09 Dec 2018 20:51:57 +0100 Received: from andi by aktux with local (Exim 4.89) (envelope-from ) id 1gW57M-0001NI-LK; Sun, 09 Dec 2018 20:51:56 +0100 From: Andreas Kemnade To: johan@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Discussions about the Letux Kernel Cc: Andreas Kemnade Subject: [PATCH v2 1/5] gnss: sirf: write data to gnss only when the gnss device is open Date: Sun, 9 Dec 2018 20:51:46 +0100 Message-Id: <20181209195150.5192-2-andreas@kemnade.info> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181209195150.5192-1-andreas@kemnade.info> References: <20181209195150.5192-1-andreas@kemnade.info> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The api forbids writing data there otherwise. Prepare for the serdev_open()/close() being a part of runtime pm. Signed-off-by: Andreas Kemnade --- Changes in v2: add locking drivers/gnss/sirf.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c index 2c22836d3ffd..ba663de1db49 100644 --- a/drivers/gnss/sirf.c +++ b/drivers/gnss/sirf.c @@ -35,6 +35,12 @@ struct sirf_data { struct gpio_desc *wakeup; int irq; bool active; + /* + * There might be races between returning data and closing the gnss + * device. + */ + struct mutex gdev_mutex; + bool opened; wait_queue_head_t power_wait; }; @@ -44,6 +50,7 @@ static int sirf_open(struct gnss_device *gdev) struct serdev_device *serdev = data->serdev; int ret; + data->opened = true; ret = serdev_device_open(serdev); if (ret) return ret; @@ -55,6 +62,7 @@ static int sirf_open(struct gnss_device *gdev) if (ret < 0) { dev_err(&gdev->dev, "failed to runtime resume: %d\n", ret); pm_runtime_put_noidle(&serdev->dev); + data->opened = false; goto err_close; } @@ -74,6 +82,9 @@ static void sirf_close(struct gnss_device *gdev) serdev_device_close(serdev); pm_runtime_put(&serdev->dev); + mutex_lock(&data->gdev_mutex); + data->opened = false; + mutex_unlock(&data->gdev_mutex); } static int sirf_write_raw(struct gnss_device *gdev, const unsigned char *buf, @@ -105,8 +116,22 @@ static int sirf_receive_buf(struct serdev_device *serdev, { struct sirf_data *data = serdev_device_get_drvdata(serdev); struct gnss_device *gdev = data->gdev; + int ret = 0; + + /* + * we might come here everytime when runtime is resumed + * and data is received. Two cases are possible + * 1. device is opened during initialisation + * 2. kernel is compiled without runtime pm + * and device is opened all the time + */ + mutex_lock(&data->gdev_mutex); + if (data->opened) + ret = gnss_insert_raw(gdev, buf, count); - return gnss_insert_raw(gdev, buf, count); + mutex_unlock(&data->gdev_mutex); + + return ret; } static const struct serdev_device_ops sirf_serdev_ops = { @@ -275,6 +300,7 @@ static int sirf_probe(struct serdev_device *serdev) data->serdev = serdev; data->gdev = gdev; + mutex_init(&data->gdev_mutex); init_waitqueue_head(&data->power_wait); serdev_device_set_drvdata(serdev, data); -- 2.11.0