[PATCH] rtc-cmos lockdep fix, irq updates
Lockdep reported cmos_suspend() and cmos_resume() calling rtc_update_irq()
with IRQs enabled; not allowed.
Also fix problems seen on some hardware, whereby false alarm IRQs could be
reported (primarily to userspace); and update two comments to match changes
in ACPI. Those make up most of this patch, by volume.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.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-cmos.c b/drivers/rtc/rtc-cmos.c
index 85bf795..7c0d609 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -59,6 +59,19 @@
static const char driver_name[] = "rtc_cmos";
+/* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
+ * always mask it against the irq enable bits in RTC_CONTROL. Bit values
+ * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
+ */
+#define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF)
+
+static inline int is_intr(u8 rtc_intr)
+{
+ if (!(rtc_intr & RTC_IRQF))
+ return 0;
+ return rtc_intr & RTC_IRQMASK;
+}
+
/*----------------------------------------------------------------*/
static int cmos_read_time(struct device *dev, struct rtc_time *t)
@@ -188,7 +201,8 @@
rtc_control &= ~RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
- if (rtc_intr)
+ rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
+ if (is_intr(rtc_intr))
rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
/* update alarm */
@@ -207,7 +221,8 @@
rtc_control |= RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
- if (rtc_intr)
+ rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
+ if (is_intr(rtc_intr))
rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
}
@@ -287,7 +302,8 @@
}
CMOS_WRITE(rtc_control, RTC_CONTROL);
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
- if (rtc_intr)
+ rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
+ if (is_intr(rtc_intr))
rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
@@ -353,12 +369,10 @@
spin_lock(&rtc_lock);
irqstat = CMOS_READ(RTC_INTR_FLAGS);
+ irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
spin_unlock(&rtc_lock);
- if (irqstat) {
- /* NOTE: irqstat may have e.g. RTC_PF set
- * even when RTC_PIE is clear...
- */
+ if (is_intr(irqstat)) {
rtc_update_irq(p, 1, irqstat);
return IRQ_HANDLED;
} else
@@ -525,25 +539,26 @@
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
int do_wake = device_may_wakeup(dev);
- unsigned char tmp, irqstat;
+ unsigned char tmp;
/* only the alarm might be a wakeup event source */
spin_lock_irq(&rtc_lock);
cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
+ unsigned char irqstat;
+
if (do_wake)
tmp &= ~(RTC_PIE|RTC_UIE);
else
tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
CMOS_WRITE(tmp, RTC_CONTROL);
irqstat = CMOS_READ(RTC_INTR_FLAGS);
- } else
- irqstat = 0;
+ irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
+ if (is_intr(irqstat))
+ rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);
+ }
spin_unlock_irq(&rtc_lock);
- if (irqstat)
- rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);
-
/* ACPI HOOK: enable ACPI_EVENT_RTC when (tmp & RTC_AIE)
* ... it'd be best if we could do that under rtc_lock.
*/
@@ -573,9 +588,10 @@
spin_lock_irq(&rtc_lock);
CMOS_WRITE(tmp, RTC_CONTROL);
tmp = CMOS_READ(RTC_INTR_FLAGS);
- spin_unlock_irq(&rtc_lock);
- if (tmp)
+ tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
+ if (is_intr(tmp))
rtc_update_irq(&cmos->rtc->class_dev, 1, tmp);
+ spin_unlock_irq(&rtc_lock);
}
pr_debug("%s: resume, ctrl %02x\n",
@@ -594,7 +610,7 @@
/*----------------------------------------------------------------*/
/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems,
- * the device node may alternatively be created as a PNP device.
+ * the device node will always be created as a PNPACPI device.
*/
#ifdef CONFIG_PNPACPI
@@ -673,7 +689,7 @@
/*----------------------------------------------------------------*/
/* Platform setup should have set up an RTC device, when PNPACPI is
- * unavailable ... this is the normal case, common even on PCs.
+ * unavailable ... this could happen even on (older) PCs.
*/
static int __init cmos_platform_probe(struct platform_device *pdev)