rtc-ds1511: 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,update}_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: Andrew Sharp <andy.sharp@lsi.com>
Cc: Thomas Hommel <thomas.hommel@gefanuc.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
index 539676e..4166b84 100644
--- a/drivers/rtc/rtc-ds1511.c
+++ b/drivers/rtc/rtc-ds1511.c
@@ -87,7 +87,6 @@
struct rtc_plat_data {
struct rtc_device *rtc;
void __iomem *ioaddr; /* virtual base address */
- unsigned long baseaddr; /* physical base address */
int size; /* amount of memory mapped */
int irq;
unsigned int irqen;
@@ -95,6 +94,7 @@
int alrm_min;
int alrm_hour;
int alrm_mday;
+ spinlock_t lock;
};
static DEFINE_SPINLOCK(ds1511_lock);
@@ -302,7 +302,7 @@
{
unsigned long flags;
- spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
+ spin_lock_irqsave(&pdata->lock, flags);
rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
RTC_ALARM_DATE);
@@ -317,7 +317,7 @@
RTC_ALARM_SEC);
rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
rtc_read(RTC_CMD1); /* clear interrupts */
- spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
+ spin_unlock_irqrestore(&pdata->lock, flags);
}
static int
@@ -362,61 +362,63 @@
{
struct platform_device *pdev = dev_id;
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
- unsigned long events = RTC_IRQF;
+ unsigned long events = 0;
+ spin_lock(&pdata->lock);
/*
* read and clear interrupt
*/
- if (!(rtc_read(RTC_CMD1) & DS1511_IRQF)) {
- return IRQ_NONE;
+ if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
+ events = RTC_IRQF;
+ if (rtc_read(RTC_ALARM_SEC) & 0x80)
+ events |= RTC_UF;
+ else
+ events |= RTC_AF;
+ if (likely(pdata->rtc))
+ rtc_update_irq(pdata->rtc, 1, events);
}
- if (rtc_read(RTC_ALARM_SEC) & 0x80) {
- events |= RTC_UF;
- } else {
- events |= RTC_AF;
- }
- rtc_update_irq(pdata->rtc, 1, events);
- return IRQ_HANDLED;
+ spin_unlock(&pdata->lock);
+ return events ? IRQ_HANDLED : IRQ_NONE;
}
- static int
-ds1511_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+static int ds1511_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;
- ds1511_rtc_update_alarm(pdata);
- break;
- case RTC_AIE_ON:
+ if (pdata->irq <= 0)
+ return -EINVAL;
+ if (enabled)
pdata->irqen |= RTC_AF;
- ds1511_rtc_update_alarm(pdata);
- break;
- case RTC_UIE_OFF:
- pdata->irqen &= ~RTC_UF;
- ds1511_rtc_update_alarm(pdata);
- break;
- case RTC_UIE_ON:
+ else
+ pdata->irqen &= ~RTC_AF;
+ ds1511_rtc_update_alarm(pdata);
+ return 0;
+}
+
+static int ds1511_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;
- ds1511_rtc_update_alarm(pdata);
- break;
- default:
- return -ENOIOCTLCMD;
- }
+ else
+ pdata->irqen &= ~RTC_UF;
+ ds1511_rtc_update_alarm(pdata);
return 0;
}
static const struct rtc_class_ops ds1511_rtc_ops = {
- .read_time = ds1511_rtc_read_time,
- .set_time = ds1511_rtc_set_time,
- .read_alarm = ds1511_rtc_read_alarm,
- .set_alarm = ds1511_rtc_set_alarm,
- .ioctl = ds1511_rtc_ioctl,
+ .read_time = ds1511_rtc_read_time,
+ .set_time = ds1511_rtc_set_time,
+ .read_alarm = ds1511_rtc_read_alarm,
+ .set_alarm = ds1511_rtc_set_alarm,
+ .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
+ .update_irq_enable = ds1511_rtc_update_irq_enable,
};
static ssize_t
@@ -492,29 +494,23 @@
{
struct rtc_device *rtc;
struct resource *res;
- struct rtc_plat_data *pdata = NULL;
+ struct rtc_plat_data *pdata;
int ret = 0;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
return -ENODEV;
}
- pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
- if (!pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
return -ENOMEM;
- }
pdata->size = res->end - res->start + 1;
- if (!request_mem_region(res->start, pdata->size, pdev->name)) {
- ret = -EBUSY;
- goto out;
- }
- pdata->baseaddr = res->start;
- pdata->size = pdata->size;
- ds1511_base = ioremap(pdata->baseaddr, pdata->size);
- if (!ds1511_base) {
- ret = -ENOMEM;
- goto out;
- }
+ if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
+ pdev->name))
+ return -EBUSY;
+ ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size);
+ if (!ds1511_base)
+ return -ENOMEM;
pdata->ioaddr = ds1511_base;
pdata->irq = platform_get_irq(pdev, 0);
@@ -540,13 +536,15 @@
dev_warn(&pdev->dev, "voltage-low detected.\n");
}
+ spin_lock_init(&pdata->lock);
+ platform_set_drvdata(pdev, pdata);
/*
* if the platform has an interrupt in mind for this device,
* then by all means, set it
*/
if (pdata->irq > 0) {
rtc_read(RTC_CMD1);
- if (request_irq(pdata->irq, ds1511_interrupt,
+ if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) {
dev_warn(&pdev->dev, "interrupt not available.\n");
@@ -556,33 +554,13 @@
rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_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;
- platform_set_drvdata(pdev, pdata);
- ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_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 (ds1511_base) {
- iounmap(ds1511_base);
- ds1511_base = NULL;
- }
- if (pdata->baseaddr) {
- release_mem_region(pdata->baseaddr, pdata->size);
- }
- kfree(pdata);
+ ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
+ if (ret)
+ rtc_device_unregister(pdata->rtc);
return ret;
}
@@ -593,19 +571,13 @@
sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
rtc_device_unregister(pdata->rtc);
- pdata->rtc = NULL;
if (pdata->irq > 0) {
/*
* disable the alarm interrupt
*/
rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
rtc_read(RTC_CMD1);
- free_irq(pdata->irq, pdev);
}
- iounmap(pdata->ioaddr);
- ds1511_base = NULL;
- release_mem_region(pdata->baseaddr, pdata->size);
- kfree(pdata);
return 0;
}