Merge remote-tracking branch 'oneiric-ubuntu/pandaboard' into pandaboard-litmus

Remote branch is from Ubuntu Oneiric (tag Ubuntu-3.0.0-1215.27) with
minor patch to the TWL-RTC code. Trying to pull this into LITMUS^RT
staging (as of 9/20/2012) to get LITMUS^RT running on the PandaBoard.

Conflicts:
	Makefile
	fs/exec.c
	include/linux/fs.h
	kernel/fork.c

6 files changed, 88 insertions, 37 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index df68618f6db..636a2ec2181 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -227,11 +227,11 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
                 alarm->time.tm_hour = now.tm_hour;
 
         /* For simplicity, only support date rollover for now */
-        if (alarm->time.tm_mday == -1) {
+        if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
                 alarm->time.tm_mday = now.tm_mday;
                 missing = day;
         }
-        if (alarm->time.tm_mon == -1) {
+        if ((unsigned)alarm->time.tm_mon >= 12) {
                 alarm->time.tm_mon = now.tm_mon;
                 if (missing == none)
                         missing = month;
@@ -636,6 +636,29 @@ void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
 }
 EXPORT_SYMBOL_GPL(rtc_irq_unregister);
 
+static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
+{
+        /*
+         * We unconditionally cancel the timer here, because otherwise
+         * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
+         * when we manage to start the timer before the callback
+         * returns HRTIMER_RESTART.
+         *
+         * We cannot use hrtimer_cancel() here as a running callback
+         * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
+         * would spin forever.
+         */
+        if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
+                return -1;
+
+        if (enabled) {
+                ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
+
+                hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
+        }
+        return 0;
+}
+
 /**
  * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
  * @rtc: the rtc device
@@ -651,21 +674,21 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled
         int err = 0;
         unsigned long flags;
 
+retry:
         spin_lock_irqsave(&rtc->irq_task_lock, flags);
         if (rtc->irq_task != NULL && task == NULL)
                 err = -EBUSY;
         if (rtc->irq_task != task)
                 err = -EACCES;
-
-        if (enabled) {
-                ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
-                hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
-        } else {
-                hrtimer_cancel(&rtc->pie_timer);
+        if (!err) {
+                if (rtc_update_hrtimer(rtc, enabled) < 0) {
+                        spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+                        cpu_relax();
+                        goto retry;
+                }
+                rtc->pie_enabled = enabled;
         }
-        rtc->pie_enabled = enabled;
         spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
-
         return err;
 }
 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
@@ -685,22 +708,20 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
         int err = 0;
         unsigned long flags;
 
-        if (freq <= 0)
+        if (freq <= 0 || freq > RTC_MAX_FREQ)
                 return -EINVAL;
-
+retry:
         spin_lock_irqsave(&rtc->irq_task_lock, flags);
         if (rtc->irq_task != NULL && task == NULL)
                 err = -EBUSY;
         if (rtc->irq_task != task)
                 err = -EACCES;
-        if (err == 0) {
+        if (!err) {
                 rtc->irq_freq = freq;
-                if (rtc->pie_enabled) {
-                        ktime_t period;
-                        hrtimer_cancel(&rtc->pie_timer);
-                        period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
-                        hrtimer_start(&rtc->pie_timer, period,
-                                        HRTIMER_MODE_REL);
+                if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
+                        spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
+                        cpu_relax();
+                        goto retry;
                 }
         }
         spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
@@ -741,6 +762,14 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
         return 0;
 }
 
+static void rtc_alarm_disable(struct rtc_device *rtc)
+{
+        if (!rtc->ops || !rtc->ops->alarm_irq_enable)
+                return;
+
+        rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
+}
+
 /**
  * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
  * @rtc rtc device
@@ -762,8 +791,10 @@ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
                 struct rtc_wkalrm alarm;
                 int err;
                 next = timerqueue_getnext(&rtc->timerqueue);
-                if (!next)
+                if (!next) {
+                        rtc_alarm_disable(rtc);
                         return;
+                }
                 alarm.time = rtc_ktime_to_tm(next->expires);
                 alarm.enabled = 1;
                 err = __rtc_set_alarm(rtc, &alarm);
@@ -825,7 +856,8 @@ again:
                 err = __rtc_set_alarm(rtc, &alarm);
                 if (err == -ETIME)
                         goto again;
-        }
+        } else
+                rtc_alarm_disable(rtc);
 
         mutex_unlock(&rtc->ops_lock);
 }
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index eda128fc1d3..64aedd8cc09 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -357,10 +357,19 @@ static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 static struct rtc_class_ops m41t80_rtc_ops = {
         .read_time = m41t80_rtc_read_time,
         .set_time = m41t80_rtc_set_time,
+        /*
+         * XXX - m41t80 alarm functionality is reported broken.
+         * until it is fixed, don't register alarm functions.
+         *
         .read_alarm = m41t80_rtc_read_alarm,
         .set_alarm = m41t80_rtc_set_alarm,
+        */
         .proc = m41t80_rtc_proc,
+        /*
+         * See above comment on broken alarm
+         *
         .alarm_irq_enable = m41t80_rtc_alarm_irq_enable,
+        */
 };
 
 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index 39e41fbdf08..51603543def 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -191,10 +191,11 @@ static irqreturn_t mxc_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 flags;
         u32 status;
         u32 events = 0;
 
-        spin_lock_irq(&pdata->rtc->irq_lock);
+        spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
         status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
         /* clear interrupt sources */
         writew(status, ioaddr + RTC_RTCISR);
@@ -217,7 +218,7 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
                 rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm);
 
         rtc_update_irq(pdata->rtc, 1, events);
-        spin_unlock_irq(&pdata->rtc->irq_lock);
+        spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
 
         return IRQ_HANDLED;
 }
diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index ff1b84bd9bb..1e80a48057e 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -312,6 +312,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
         int ret;
         struct pl031_local *ldata;
         struct rtc_class_ops *ops = id->data;
+        unsigned long time;
 
         ret = amba_request_regions(adev, NULL);
         if (ret)
@@ -339,11 +340,27 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
         dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision);
 
         /* Enable the clockwatch on ST Variants */
-        if ((ldata->hw_designer == AMBA_VENDOR_ST) &&
-            (ldata->hw_revision > 1))
+        if (ldata->hw_designer == AMBA_VENDOR_ST)
                 writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN,
                        ldata->base + RTC_CR);
 
+        /*
+         * On ST PL031 variants, the RTC reset value does not provide correct
+         * weekday for 2000-01-01. Correct the erroneous sunday to saturday.
+         */
+        if (ldata->hw_designer == AMBA_VENDOR_ST) {
+                if (readl(ldata->base + RTC_YDR) == 0x2000) {
+                        time = readl(ldata->base + RTC_DR);
+                        if ((time &
+                             (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))
+                            == 0x02120000) {
+                                time = time | (0x7 << RTC_WDAY_SHIFT);
+                                writel(0x2000, ldata->base + RTC_YLR);
+                                writel(time, ldata->base + RTC_LR);
+                        }
+                }
+        }
+
         ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
                                         THIS_MODULE);
         if (IS_ERR(ldata->rtc)) {
diff --git a/drivers/rtc/rtc-tegra.c b/drivers/rtc/rtc-tegra.c
index 2fc31aac3f4..75259fe3860 100644
--- a/drivers/rtc/rtc-tegra.c
+++ b/drivers/rtc/rtc-tegra.c
@@ -343,7 +343,7 @@ static int __devinit tegra_rtc_probe(struct platform_device *pdev)
 
         /* set context info. */
         info->pdev = pdev;
-        info->tegra_rtc_lock = __SPIN_LOCK_UNLOCKED(info->tegra_rtc_lock);
+        spin_lock_init(&info->tegra_rtc_lock);
 
         platform_set_drvdata(pdev, info);
 
diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
index f9a2799c44d..9d51b40f164 100644
--- a/drivers/rtc/rtc-twl.c
+++ b/drivers/rtc/rtc-twl.c
@@ -362,14 +362,6 @@ static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
         int res;
         u8 rd_reg;
 
-#ifdef CONFIG_LOCKDEP
-        /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
-         * we don't want and can't tolerate.  Although it might be
-         * friendlier not to borrow this thread context...
-         */
-        local_irq_enable();
-#endif
-
         res = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
         if (res)
                 goto out;
@@ -462,9 +454,9 @@ static int __devinit twl_rtc_probe(struct platform_device *pdev)
         if (ret < 0)
                 goto out1;
 
-        ret = request_irq(irq, twl_rtc_interrupt,
-                                IRQF_TRIGGER_RISING,
-                                dev_name(&rtc->dev), rtc);
+        ret = request_threaded_irq(irq, NULL, twl_rtc_interrupt,
++                                  IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+                                   dev_name(&rtc->dev), rtc);
         if (ret < 0) {
                 dev_err(&pdev->dev, "IRQ is not free.\n");
                 goto out1;