Merge tag 'pm+acpi-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes for recent regressions (ACPI resources management,
  suspend-to-idle), stable-candidate fixes (ACPI backlight), fixes
  related to the wakeup IRQ management changes made in v3.18, other
  fixes (suspend-to-idle, cpufreq ppc driver) and a couple of cleanups
  (suspend-to-idle, generic power domains, ACPI backlight).

  Specifics:

   - Fix ACPI resources management problems introduced by the recent
     rework of the code in question (Jiang Liu) and a build issue
     introduced by those changes (Joachim Nilsson).

   - Fix a recent suspend-to-idle regression on systems where entering
     idle states causes local timers to stop, prevent suspend-to-idle
     from crashing in restricted configurations (no cpuidle driver,
     cpuidle disabled etc.) and clean up the idle loop somewhat while at
     it (Rafael J Wysocki).

   - Fix build problem in the cpufreq ppc driver (Geert Uytterhoeven).

   - Allow the ACPI backlight driver module to be loaded if ACPI is
     disabled which helps the i915 driver in those configurations
     (stable-candidate) and change the code to help debug unusual use
     cases (Chris Wilson).

   - Wakeup IRQ management changes in v3.18 caused some drivers on the
     at91 platform to trigger a warning from the IRQ core related to an
     unexpected combination of interrupt action handler flags.  However,
     on at91 a timer IRQ is shared with some other devices (including
     system wakeup ones) and that leads to the unusual combination of
     flags in question.

     To make it possible to avoid the warning introduce a new interrupt
     action handler flag (which can be used by drivers to indicate the
     special case to the core) and rework the problematic at91 drivers
     to use it and work as expected during system suspend/resume.  From
     Boris Brezillon, Rafael J Wysocki and Mark Rutland.

   - Clean up the generic power domains subsystem's debugfs interface
     (Kevin Hilman)"

* tag 'pm+acpi-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  genirq / PM: describe IRQF_COND_SUSPEND
  tty: serial: atmel: rework interrupt and wakeup handling
  watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND
  cpuidle / sleep: Use broadcast timer for states that stop local timer
  clk: at91: implement suspend/resume for the PMC irqchip
  rtc: at91rm9200: rework wakeup and interrupt handling
  rtc: at91sam9: rework wakeup and interrupt handling
  PM / wakeup: export pm_system_wakeup symbol
  genirq / PM: Add flag for shared NO_SUSPEND interrupt lines
  ACPI / video: Propagate the error code for acpi_video_register
  ACPI / video: Load the module even if ACPI is disabled
  PM / Domains: cleanup: rename gpd -> genpd in debugfs interface
  cpufreq: ppc: Add missing #include <asm/smp.h>
  x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs
  x86/PCI/ACPI: Ignore resources consumed by host bridge itself
  cpuidle: Clean up fallback handling in cpuidle_idle_call()
  cpuidle / sleep: Do sanity checks in cpuidle_enter_freeze() too
  idle / sleep: Avoid excessive disabling and enabling interrupts
  PCI: versatile: Update for list_for_each_entry() API change
  genirq / PM: better describe IRQF_NO_SUSPEND semantics

1 files changed, 61 insertions, 12 deletions

diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index 2183fd2750ab..5ccaee32df72 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -23,6 +23,7 @@
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
+#include <linux/suspend.h>
 #include <linux/clk.h>
 
 /*
@@ -77,6 +78,9 @@ struct sam9_rtc {
 	unsigned int		gpbr_offset;
 	int 			irq;
 	struct clk		*sclk;
+	bool			suspended;
+	unsigned long		events;
+	spinlock_t		lock;
 };
 
 #define rtt_readl(rtc, field) \
@@ -271,14 +275,9 @@ static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 	return 0;
 }
 
-/*
- * IRQ handler for the RTC
- */
-static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
+static irqreturn_t at91_rtc_cache_events(struct sam9_rtc *rtc)
 {
-	struct sam9_rtc *rtc = _rtc;
 	u32 sr, mr;
-	unsigned long events = 0;
 
 	/* Shared interrupt may be for another device.  Note: reading
 	 * SR clears it, so we must only read it in this irq handler!
@@ -290,18 +289,54 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
 
 	/* alarm status */
 	if (sr & AT91_RTT_ALMS)
-		events |= (RTC_AF | RTC_IRQF);
+		rtc->events |= (RTC_AF | RTC_IRQF);
 
 	/* timer update/increment */
 	if (sr & AT91_RTT_RTTINC)
-		events |= (RTC_UF | RTC_IRQF);
+		rtc->events |= (RTC_UF | RTC_IRQF);
+
+	return IRQ_HANDLED;
+}
+
+static void at91_rtc_flush_events(struct sam9_rtc *rtc)
+{
+	if (!rtc->events)
+		return;
 
-	rtc_update_irq(rtc->rtcdev, 1, events);
+	rtc_update_irq(rtc->rtcdev, 1, rtc->events);
+	rtc->events = 0;
 
 	pr_debug("%s: num=%ld, events=0x%02lx\n", __func__,
-		events >> 8, events & 0x000000FF);
+		rtc->events >> 8, rtc->events & 0x000000FF);
+}
 
-	return IRQ_HANDLED;
+/*
+ * IRQ handler for the RTC
+ */
+static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc)
+{
+	struct sam9_rtc *rtc = _rtc;
+	int ret;
+
+	spin_lock(&rtc->lock);
+
+	ret = at91_rtc_cache_events(rtc);
+
+	/* We're called in suspended state */
+	if (rtc->suspended) {
+		/* Mask irqs coming from this peripheral */
+		rtt_writel(rtc, MR,
+			   rtt_readl(rtc, MR) &
+			   ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
+		/* Trigger a system wakeup */
+		pm_system_wakeup();
+	} else {
+		at91_rtc_flush_events(rtc);
+	}
+
+	spin_unlock(&rtc->lock);
+
+	return ret;
 }
 
 static const struct rtc_class_ops at91_rtc_ops = {
@@ -421,7 +456,8 @@ static int at91_rtc_probe(struct platform_device *pdev)
 
 	/* register irq handler after we know what name we'll use */
 	ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt,
-				IRQF_SHARED, dev_name(&rtc->rtcdev->dev), rtc);
+			       IRQF_SHARED | IRQF_COND_SUSPEND,
+			       dev_name(&rtc->rtcdev->dev), rtc);
 	if (ret) {
 		dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
 		return ret;
@@ -482,7 +518,12 @@ static int at91_rtc_suspend(struct device *dev)
 	rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
 	if (rtc->imr) {
 		if (device_may_wakeup(dev) && (mr & AT91_RTT_ALMIEN)) {
+			unsigned long flags;
+
 			enable_irq_wake(rtc->irq);
+			spin_lock_irqsave(&rtc->lock, flags);
+			rtc->suspended = true;
+			spin_unlock_irqrestore(&rtc->lock, flags);
 			/* don't let RTTINC cause wakeups */
 			if (mr & AT91_RTT_RTTINCIEN)
 				rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
@@ -499,10 +540,18 @@ static int at91_rtc_resume(struct device *dev)
 	u32		mr;
 
 	if (rtc->imr) {
+		unsigned long flags;
+
 		if (device_may_wakeup(dev))
 			disable_irq_wake(rtc->irq);
 		mr = rtt_readl(rtc, MR);
 		rtt_writel(rtc, MR, mr | rtc->imr);
+
+		spin_lock_irqsave(&rtc->lock, flags);
+		rtc->suspended = false;
+		at91_rtc_cache_events(rtc);
+		at91_rtc_flush_events(rtc);
+		spin_unlock_irqrestore(&rtc->lock, flags);
 	}
 
 	return 0;