From patchwork Wed Oct 14 14:15:46 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atsushi Nemoto X-Patchwork-Id: 35970 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from mail-pz0-f167.google.com (mail-pz0-f167.google.com [209.85.222.167]) by ozlabs.org (Postfix) with ESMTP id 88E04B7334 for ; Thu, 15 Oct 2009 01:15:51 +1100 (EST) Received: by pzk39 with SMTP id 39so2510169pzk.11 for ; Wed, 14 Oct 2009 07:15:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=beta; h=domainkey-signature:received:received:x-sender:x-apparently-to :received:received:received:received-spf:received:from:to:cc:subject :date:message-id:x-mailer:reply-to:sender:precedence:x-google-loop :mailing-list:list-id:list-post:list-help:list-unsubscribe :x-beenthere-env:x-beenthere; bh=Xn/NJqGL1CyKyxCg7NRaQufkq28lPMz25jQAyU6IZO0=; b=oaiF54XV3NgHe4KJe3yATUuUk9MU25ZyTXpFf1oa8Od7fE0n2xl4fnn5bmWm2YNruw VdcQlXgyJRCvxN3TiL+8FOPuKXqo/+k+4F/geeHBJ9K8RtTD4VzL4FS1xWfMU5uuiEnC O2LZw0Vj+ieaAERu3eUKGb9hKDATEBhYsmFbc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlegroups.com; s=beta; h=x-sender:x-apparently-to:received-spf:authentication-results:from :to:cc:subject:date:message-id:x-mailer:reply-to:sender:precedence :x-google-loop:mailing-list:list-id:list-post:list-help :list-unsubscribe:x-beenthere-env:x-beenthere; b=2ESPYqCctrG9cRMBfRKsrdKp8Api+DknNvPgKf+8MkFF1JaPHCsYlZIAsARmauUQp+ u41MGWLZ9E9q1UkddxMeCuxObL0NCQypqXnTqRIuIvDo6di9CEDQHPIhHrQQMXPIQ4Fa +KpKASwt7jtbRUsuYoly8bY8TsnnowxWHnGZ4= Received: by 10.142.152.2 with SMTP id z2mr170518wfd.20.1255529748893; Wed, 14 Oct 2009 07:15:48 -0700 (PDT) Received: by 10.106.114.12 with SMTP id m12gr2961prc.0; Wed, 14 Oct 2009 07:15:48 -0700 (PDT) X-Sender: anemo@mba.ocn.ne.jp X-Apparently-To: rtc-linux@googlegroups.com Received: by 10.140.200.14 with SMTP id x14mr1432996rvf.25.1255529747406; Wed, 14 Oct 2009 07:15:47 -0700 (PDT) Received: by 10.140.200.14 with SMTP id x14mr1432995rvf.25.1255529747387; Wed, 14 Oct 2009 07:15:47 -0700 (PDT) Received: from smtp.mba.ocn.ne.jp (mba.ocn.ne.jp [122.28.14.163]) by gmr-mx.google.com with ESMTP id 25si121629pzk.11.2009.10.14.07.15.46; Wed, 14 Oct 2009 07:15:47 -0700 (PDT) Received-SPF: pass (google.com: domain of anemo@mba.ocn.ne.jp designates 122.28.14.163 as permitted sender) client-ip=122.28.14.163; Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of anemo@mba.ocn.ne.jp designates 122.28.14.163 as permitted sender) smtp.mail=anemo@mba.ocn.ne.jp Received: from localhost.localdomain (p8042-ipad301funabasi.chiba.ocn.ne.jp [122.18.2.42]) by smtp.mba.ocn.ne.jp (Postfix) with ESMTP id 888176D9D; Wed, 14 Oct 2009 23:15:45 +0900 (JST) From: Atsushi Nemoto To: Alessandro Zummo Cc: Thomas Hommel , rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: [rtc-linux] [PATCH] rtc-stk17ta8: Fix races around device registration Date: Wed, 14 Oct 2009 23:15:46 +0900 Message-Id: <1255529746-1296-1-git-send-email-anemo@mba.ocn.ne.jp> X-Mailer: git-send-email 1.5.6.5 Reply-To: rtc-linux@googlegroups.com Sender: rtc-linux@googlegroups.com Precedence: bulk X-Google-Loop: groups Mailing-List: list rtc-linux@googlegroups.com; contact rtc-linux+owner@googlegroups.com List-Id: List-Post: List-Help: List-Unsubscribe: , X-BeenThere-Env: rtc-linux@googlegroups.com X-BeenThere: rtc-linux@googlegroups.com - Call dev_set_drvdata before rtc device creation. - Use its own spinlock instead of rtc->irq_lock. Because pdata->rtc must be initialized to use the irq_lock (pdata->rtc->irq_lock). There is a small window which rtc methods can be called before pdata->rtc is initialized. And there is no need use the irq_lock to protect hardware registers. The driver's own spinlock shoule be enough. - Check pdata->rtc before calling rtc_update_irq. - Use alarm_irq_enable and remove ioctl routine. - Use devres APIs and simplify error/remove path. These fixes are ported from ds1553 driver and just compile-tested only. Signed-off-by: Atsushi Nemoto --- Changes from previous version: * Rebase on rtc-fix-driver-data-issues-in-several-rtc-drivers.patch * Refine commit message drivers/rtc/rtc-stk17ta8.c | 114 +++++++++++++++++-------------------------- 1 files changed, 45 insertions(+), 69 deletions(-) diff --git a/drivers/rtc/rtc-stk17ta8.c b/drivers/rtc/rtc-stk17ta8.c index 78d9d07..df3b6c5 100644 --- a/drivers/rtc/rtc-stk17ta8.c +++ b/drivers/rtc/rtc-stk17ta8.c @@ -62,7 +62,6 @@ struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; - unsigned long baseaddr; unsigned long last_jiffies; int irq; unsigned int irqen; @@ -70,6 +69,7 @@ struct rtc_plat_data { int alrm_min; int alrm_hour; int alrm_mday; + spinlock_t lock; }; static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm) @@ -142,7 +142,7 @@ static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata) unsigned long irqflags; u8 flags; - spin_lock_irqsave(&pdata->rtc->irq_lock, irqflags); + spin_lock_irqsave(&pdata->lock, irqflags); flags = readb(ioaddr + RTC_FLAGS); writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS); @@ -162,7 +162,7 @@ static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata) writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS); readb(ioaddr + RTC_FLAGS); /* clear interrupts */ writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS); - spin_unlock_irqrestore(&pdata->rtc->irq_lock, irqflags); + spin_unlock_irqrestore(&pdata->lock, irqflags); } static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) @@ -202,48 +202,45 @@ static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id) struct platform_device *pdev = dev_id; struct rtc_plat_data *pdata = platform_get_drvdata(pdev); void __iomem *ioaddr = pdata->ioaddr; - unsigned long events = RTC_IRQF; + unsigned long events = 0; + spin_lock(&pdata->lock); /* read and clear interrupt */ - if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF)) - return IRQ_NONE; - if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80) - events |= RTC_UF; - else - events |= RTC_AF; - rtc_update_irq(pdata->rtc, 1, events); - return IRQ_HANDLED; + if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) { + events = RTC_IRQF; + if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80) + events |= RTC_UF; + else + events |= RTC_AF; + if (likely(pdata->rtc)) + rtc_update_irq(pdata->rtc, 1, events); + } + spin_unlock(&pdata->lock); + return events ? IRQ_HANDLED : IRQ_NONE; } -static int stk17ta8_rtc_ioctl(struct device *dev, unsigned int cmd, - unsigned long arg) +static int stk17ta8_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); if (pdata->irq <= 0) - return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */ - switch (cmd) { - case RTC_AIE_OFF: - pdata->irqen &= ~RTC_AF; - stk17ta8_rtc_update_alarm(pdata); - break; - case RTC_AIE_ON: + return -EINVAL; + if (enabled) pdata->irqen |= RTC_AF; - stk17ta8_rtc_update_alarm(pdata); - break; - default: - return -ENOIOCTLCMD; - } + else + pdata->irqen &= ~RTC_AF; + stk17ta8_rtc_update_alarm(pdata); return 0; } static const struct rtc_class_ops stk17ta8_rtc_ops = { - .read_time = stk17ta8_rtc_read_time, - .set_time = stk17ta8_rtc_set_time, - .read_alarm = stk17ta8_rtc_read_alarm, - .set_alarm = stk17ta8_rtc_set_alarm, - .ioctl = stk17ta8_rtc_ioctl, + .read_time = stk17ta8_rtc_read_time, + .set_time = stk17ta8_rtc_set_time, + .read_alarm = stk17ta8_rtc_read_alarm, + .set_alarm = stk17ta8_rtc_set_alarm, + .alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable, }; static ssize_t stk17ta8_nvram_read(struct kobject *kobj, @@ -292,26 +289,22 @@ static int __init stk17ta8_rtc_probe(struct platform_device *pdev) unsigned int cal; unsigned int flags; struct rtc_plat_data *pdata; - void __iomem *ioaddr = NULL; + void __iomem *ioaddr; int ret = 0; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENODEV; - pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; - if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) { - ret = -EBUSY; - goto out; - } - pdata->baseaddr = res->start; - ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE); - if (!ioaddr) { - ret = -ENOMEM; - goto out; - } + if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE, + pdev->name)) + return -EBUSY; + ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE); + if (!ioaddr) + return -ENOMEM; pdata->ioaddr = ioaddr; pdata->irq = platform_get_irq(pdev, 0); @@ -327,9 +320,13 @@ static int __init stk17ta8_rtc_probe(struct platform_device *pdev) if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF) dev_warn(&pdev->dev, "voltage-low detected.\n"); + spin_lock_init(&pdata->lock); + pdata->last_jiffies = jiffies; + platform_set_drvdata(pdev, pdata); if (pdata->irq > 0) { writeb(0, ioaddr + RTC_INTERRUPTS); - if (request_irq(pdata->irq, stk17ta8_rtc_interrupt, + if (devm_request_irq(&pdev->dev, pdata->irq, + stk17ta8_rtc_interrupt, IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) { dev_warn(&pdev->dev, "interrupt not available.\n"); @@ -337,30 +334,14 @@ static int __init stk17ta8_rtc_probe(struct platform_device *pdev) } } - pdata->last_jiffies = jiffies; - platform_set_drvdata(pdev, pdata); - pdata->rtc = rtc_device_register(pdev->name, &pdev->dev, &stk17ta8_rtc_ops, THIS_MODULE); - if (IS_ERR(pdata->rtc)) { - ret = PTR_ERR(pdata->rtc); - goto out; - } + if (IS_ERR(pdata->rtc)) + return PTR_ERR(pdata->rtc); ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr); - if (ret) { + if (ret) rtc_device_unregister(pdata->rtc); - goto out; - } - return 0; - out: - if (pdata->irq > 0) - free_irq(pdata->irq, pdev); - if (ioaddr) - iounmap(ioaddr); - if (pdata->baseaddr) - release_mem_region(pdata->baseaddr, RTC_REG_SIZE); - kfree(pdata); return ret; } @@ -370,13 +351,8 @@ static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev) sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr); rtc_device_unregister(pdata->rtc); - if (pdata->irq > 0) { + if (pdata->irq > 0) writeb(0, pdata->ioaddr + RTC_INTERRUPTS); - free_irq(pdata->irq, pdev); - } - iounmap(pdata->ioaddr); - release_mem_region(pdata->baseaddr, RTC_REG_SIZE); - kfree(pdata); return 0; }