From patchwork Mon Jan 23 10:41:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Ripard X-Patchwork-Id: 9532087 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2A7EB60434 for ; Mon, 23 Jan 2017 10:44:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1C7F827E3E for ; Mon, 23 Jan 2017 10:44:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0FBC027F07; Mon, 23 Jan 2017 10:44:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00 autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8FB3227E3E for ; Mon, 23 Jan 2017 10:44:30 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cVc6n-00008b-Qf; Mon, 23 Jan 2017 10:44:21 +0000 Received: from mail.free-electrons.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cVc4u-0007AG-V8 for linux-arm-kernel@lists.infradead.org; Mon, 23 Jan 2017 10:42:28 +0000 Received: by mail.free-electrons.com (Postfix, from userid 110) id 2A51120C15; Mon, 23 Jan 2017 11:42:09 +0100 (CET) Received: from localhost (LStLambert-657-1-97-87.w90-63.abo.wanadoo.fr [90.63.216.87]) by mail.free-electrons.com (Postfix) with ESMTPSA id F1B0620719; Mon, 23 Jan 2017 11:41:58 +0100 (CET) From: Maxime Ripard To: Alexandre Belloni , Alessandro Zummo , Chen-Yu Tsai Subject: [PATCH v2 2/7] rtc: sun6i: Add some locking Date: Mon, 23 Jan 2017 11:41:47 +0100 Message-Id: X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170123_024225_304463_81169CEA X-CRM114-Status: GOOD ( 14.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, rtc-linux@googlegroups.com, stable@vger.kernel.org, Rob Herring , Maxime Ripard , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some registers have a read-modify-write access pattern that are not atomic. Add some locking to prevent from concurrent accesses. Cc: stable@vger.kernel.org Acked-by: Chen-Yu Tsai Signed-off-by: Maxime Ripard --- drivers/rtc/rtc-sun6i.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index a6136cb99851..5527f5eb597b 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -114,13 +114,17 @@ struct sun6i_rtc_dev { void __iomem *base; int irq; unsigned long alarm; + + spinlock_t lock; }; static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id) { struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id; + irqreturn_t ret = IRQ_NONE; u32 val; + spin_lock(&chip->lock); val = readl(chip->base + SUN6I_ALRM_IRQ_STA); if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) { @@ -129,10 +133,11 @@ static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id) rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); - return IRQ_HANDLED; + ret = IRQ_HANDLED; } + spin_unlock(&chip->lock); - return IRQ_NONE; + return ret; } static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) @@ -140,6 +145,7 @@ static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) u32 alrm_val = 0; u32 alrm_irq_val = 0; u32 alrm_wake_val = 0; + unsigned long flags; if (to) { alrm_val = SUN6I_ALRM_EN_CNT_EN; @@ -150,9 +156,11 @@ static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) chip->base + SUN6I_ALRM_IRQ_STA); } + spin_lock_irqsave(&chip->lock, flags); writel(alrm_val, chip->base + SUN6I_ALRM_EN); writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN); writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG); + spin_unlock_irqrestore(&chip->lock, flags); } static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) @@ -191,11 +199,15 @@ static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); + unsigned long flags; u32 alrm_st; u32 alrm_en; + spin_lock_irqsave(&chip->lock, flags); alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN); alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA); + spin_unlock_irqrestore(&chip->lock, flags); + wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN); wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN); rtc_time_to_tm(chip->alarm, &wkalrm->time); @@ -356,6 +368,7 @@ static int sun6i_rtc_probe(struct platform_device *pdev) chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; + spin_lock_init(&rtc->lock); platform_set_drvdata(pdev, chip); chip->dev = &pdev->dev;