rtc-stk17ta8: fix races around device registration
- 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 <anemo@mba.ocn.ne.jp> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Cc: Thomas Hommel <thomas.hommel@gefanuc.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>hifive-unleashed-5.1
Atsushi Nemoto
Linus Torvalds
parent
ac18eb622f
commit
3151520d88
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@ -62,7 +62,6 @@
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struct rtc_plat_data {
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struct rtc_device *rtc;
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void __iomem *ioaddr;
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unsigned long baseaddr;
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unsigned long last_jiffies;
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int irq;
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unsigned int irqen;
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@ -70,6 +69,7 @@ struct rtc_plat_data {
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int alrm_min;
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int alrm_hour;
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int alrm_mday;
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spinlock_t lock;
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};
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static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
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@ -142,7 +142,7 @@ static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
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unsigned long irqflags;
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u8 flags;
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spin_lock_irqsave(&pdata->rtc->irq_lock, irqflags);
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spin_lock_irqsave(&pdata->lock, irqflags);
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flags = readb(ioaddr + RTC_FLAGS);
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writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
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@ -162,7 +162,7 @@ static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
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writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
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readb(ioaddr + RTC_FLAGS); /* clear interrupts */
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writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
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spin_unlock_irqrestore(&pdata->rtc->irq_lock, irqflags);
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spin_unlock_irqrestore(&pdata->lock, irqflags);
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}
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static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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@ -202,48 +202,45 @@ static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
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struct platform_device *pdev = dev_id;
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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void __iomem *ioaddr = pdata->ioaddr;
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unsigned long events = RTC_IRQF;
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unsigned long events = 0;
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spin_lock(&pdata->lock);
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/* read and clear interrupt */
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if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF))
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return IRQ_NONE;
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if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
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events |= RTC_UF;
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else
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events |= RTC_AF;
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rtc_update_irq(pdata->rtc, 1, events);
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return IRQ_HANDLED;
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if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
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events = RTC_IRQF;
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if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
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events |= RTC_UF;
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else
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events |= RTC_AF;
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if (likely(pdata->rtc))
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rtc_update_irq(pdata->rtc, 1, events);
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}
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spin_unlock(&pdata->lock);
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return events ? IRQ_HANDLED : IRQ_NONE;
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}
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static int stk17ta8_rtc_ioctl(struct device *dev, unsigned int cmd,
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unsigned long arg)
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static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
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unsigned int enabled)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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if (pdata->irq <= 0)
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return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
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switch (cmd) {
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case RTC_AIE_OFF:
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pdata->irqen &= ~RTC_AF;
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stk17ta8_rtc_update_alarm(pdata);
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break;
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case RTC_AIE_ON:
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return -EINVAL;
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if (enabled)
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pdata->irqen |= RTC_AF;
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stk17ta8_rtc_update_alarm(pdata);
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break;
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default:
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return -ENOIOCTLCMD;
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}
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else
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pdata->irqen &= ~RTC_AF;
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stk17ta8_rtc_update_alarm(pdata);
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return 0;
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}
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static const struct rtc_class_ops stk17ta8_rtc_ops = {
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.read_time = stk17ta8_rtc_read_time,
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.set_time = stk17ta8_rtc_set_time,
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.read_alarm = stk17ta8_rtc_read_alarm,
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.set_alarm = stk17ta8_rtc_set_alarm,
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.ioctl = stk17ta8_rtc_ioctl,
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.read_time = stk17ta8_rtc_read_time,
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.set_time = stk17ta8_rtc_set_time,
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.read_alarm = stk17ta8_rtc_read_alarm,
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.set_alarm = stk17ta8_rtc_set_alarm,
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.alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable,
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};
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static ssize_t stk17ta8_nvram_read(struct kobject *kobj,
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@ -292,26 +289,22 @@ static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
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unsigned int cal;
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unsigned int flags;
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struct rtc_plat_data *pdata;
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void __iomem *ioaddr = NULL;
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void __iomem *ioaddr;
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int ret = 0;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
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pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
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ret = -EBUSY;
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goto out;
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}
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pdata->baseaddr = res->start;
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ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
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if (!ioaddr) {
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ret = -ENOMEM;
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goto out;
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}
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if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
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pdev->name))
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return -EBUSY;
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ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
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if (!ioaddr)
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return -ENOMEM;
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pdata->ioaddr = ioaddr;
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pdata->irq = platform_get_irq(pdev, 0);
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@ -327,9 +320,13 @@ static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
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if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
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dev_warn(&pdev->dev, "voltage-low detected.\n");
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spin_lock_init(&pdata->lock);
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pdata->last_jiffies = jiffies;
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platform_set_drvdata(pdev, pdata);
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if (pdata->irq > 0) {
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writeb(0, ioaddr + RTC_INTERRUPTS);
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if (request_irq(pdata->irq, stk17ta8_rtc_interrupt,
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if (devm_request_irq(&pdev->dev, pdata->irq,
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stk17ta8_rtc_interrupt,
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IRQF_DISABLED | IRQF_SHARED,
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pdev->name, pdev) < 0) {
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dev_warn(&pdev->dev, "interrupt not available.\n");
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@ -337,30 +334,14 @@ static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
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}
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}
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pdata->last_jiffies = jiffies;
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platform_set_drvdata(pdev, pdata);
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pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
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&stk17ta8_rtc_ops, THIS_MODULE);
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if (IS_ERR(pdata->rtc)) {
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ret = PTR_ERR(pdata->rtc);
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goto out;
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}
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if (IS_ERR(pdata->rtc))
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return PTR_ERR(pdata->rtc);
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ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
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if (ret) {
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if (ret)
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rtc_device_unregister(pdata->rtc);
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goto out;
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}
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return 0;
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out:
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if (pdata->irq > 0)
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free_irq(pdata->irq, pdev);
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if (ioaddr)
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iounmap(ioaddr);
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if (pdata->baseaddr)
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release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
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kfree(pdata);
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return ret;
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}
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@ -370,13 +351,8 @@ static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
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sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
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rtc_device_unregister(pdata->rtc);
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if (pdata->irq > 0) {
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if (pdata->irq > 0)
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writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
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free_irq(pdata->irq, pdev);
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}
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iounmap(pdata->ioaddr);
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release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
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kfree(pdata);
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return 0;
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}
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