From: Atsushi Nemoto Date: Wed, 16 Dec 2009 00:46:01 +0000 (-0800) Subject: rtc-ds1553: fix races around device registration X-Git-Tag: v2.6.33-rc1~71^2~152 X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=618161f71cb10ff9bfe74c9bd766faf339f98274;p=net-next-2.6.git rtc-ds1553: fix races around device registration * Call dev_set_drvdata before rtc device creation * Use its own spinlock instead of rtc->irq_lock * Check pdata->rtc before calling rtc_update_irq * Use {alarm,update}_irq_enable and remove ioctl routine * Use devres APIs and simplify error/remove path Signed-off-by: Atsushi Nemoto Acked-by: Alessandro Zummo Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c index 717288527c6..dadd0f517d5 100644 --- a/drivers/rtc/rtc-ds1553.c +++ b/drivers/rtc/rtc-ds1553.c @@ -18,7 +18,7 @@ #include #include -#define DRV_VERSION "0.2" +#define DRV_VERSION "0.3" #define RTC_REG_SIZE 0x2000 #define RTC_OFFSET 0x1ff0 @@ -61,7 +61,6 @@ struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; - resource_size_t baseaddr; unsigned long last_jiffies; int irq; unsigned int irqen; @@ -69,6 +68,7 @@ struct rtc_plat_data { int alrm_min; int alrm_hour; int alrm_mday; + spinlock_t lock; }; static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm) @@ -139,7 +139,7 @@ static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata) void __iomem *ioaddr = pdata->ioaddr; unsigned long flags; - spin_lock_irqsave(&pdata->rtc->irq_lock, flags); + spin_lock_irqsave(&pdata->lock, flags); writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ? 0x80 : bin2bcd(pdata->alrm_mday), ioaddr + RTC_DATE_ALARM); @@ -154,7 +154,7 @@ static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata) ioaddr + RTC_SECONDS_ALARM); writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS); readb(ioaddr + RTC_FLAGS); /* clear interrupts */ - spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); + spin_unlock_irqrestore(&pdata->lock, flags); } static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) @@ -194,56 +194,61 @@ static irqreturn_t ds1553_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 ds1553_rtc_ioctl(struct device *dev, unsigned int cmd, - unsigned long arg) +static int ds1553_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; - ds1553_rtc_update_alarm(pdata); - break; - case RTC_AIE_ON: + return -EINVAL; + if (enabled) pdata->irqen |= RTC_AF; - ds1553_rtc_update_alarm(pdata); - break; - case RTC_UIE_OFF: - pdata->irqen &= ~RTC_UF; - ds1553_rtc_update_alarm(pdata); - break; - case RTC_UIE_ON: + else + pdata->irqen &= ~RTC_AF; + ds1553_rtc_update_alarm(pdata); + return 0; +} + +static int ds1553_rtc_update_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 -EINVAL; + if (enabled) pdata->irqen |= RTC_UF; - ds1553_rtc_update_alarm(pdata); - break; - default: - return -ENOIOCTLCMD; - } + else + pdata->irqen &= ~RTC_UF; + ds1553_rtc_update_alarm(pdata); return 0; } static const struct rtc_class_ops ds1553_rtc_ops = { - .read_time = ds1553_rtc_read_time, - .set_time = ds1553_rtc_set_time, - .read_alarm = ds1553_rtc_read_alarm, - .set_alarm = ds1553_rtc_set_alarm, - .ioctl = ds1553_rtc_ioctl, + .read_time = ds1553_rtc_read_time, + .set_time = ds1553_rtc_set_time, + .read_alarm = ds1553_rtc_read_alarm, + .set_alarm = ds1553_rtc_set_alarm, + .alarm_irq_enable = ds1553_rtc_alarm_irq_enable, + .update_irq_enable = ds1553_rtc_update_irq_enable, }; static ssize_t ds1553_nvram_read(struct kobject *kobj, @@ -291,26 +296,23 @@ static int __devinit ds1553_rtc_probe(struct platform_device *pdev) struct rtc_device *rtc; struct resource *res; unsigned int cen, sec; - struct rtc_plat_data *pdata = NULL; - void __iomem *ioaddr = NULL; + struct rtc_plat_data *pdata; + 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); @@ -326,9 +328,13 @@ static int __devinit ds1553_rtc_probe(struct platform_device *pdev) if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF) 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, ds1553_rtc_interrupt, + if (devm_request_irq(&pdev->dev, pdata->irq, + ds1553_rtc_interrupt, IRQF_DISABLED, pdev->name, pdev) < 0) { dev_warn(&pdev->dev, "interrupt not available.\n"); pdata->irq = 0; @@ -337,27 +343,13 @@ static int __devinit ds1553_rtc_probe(struct platform_device *pdev) rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1553_rtc_ops, THIS_MODULE); - if (IS_ERR(rtc)) { - ret = PTR_ERR(rtc); - goto out; - } + if (IS_ERR(rtc)) + return PTR_ERR(rtc); pdata->rtc = rtc; - pdata->last_jiffies = jiffies; - platform_set_drvdata(pdev, pdata); + ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr); if (ret) - goto out; - return 0; - out: - if (pdata->rtc) - rtc_device_unregister(pdata->rtc); - 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); + rtc_device_unregister(rtc); return ret; } @@ -367,13 +359,8 @@ static int __devexit ds1553_rtc_remove(struct platform_device *pdev) sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_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; }