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Message-Id: <1255529746-1296-1-git-send-email-anemo@mba.ocn.ne.jp>
Date: Wed, 14 Oct 2009 23:15:46 +0900
From: Atsushi Nemoto <anemo@....ocn.ne.jp>
To: Alessandro Zummo <alessandro.zummo@...ertech.it>
Cc: Thomas Hommel <thomas.hommel@...anuc.com>,
rtc-linux@...glegroups.com, linux-kernel@...r.kernel.org,
akpm@...ux-foundation.org
Subject: [PATCH] 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@....ocn.ne.jp>
---
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;
}
--
1.5.6.5
--
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