Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "The timer departement delivers:

   - a regression fix for the NTP code along with a proper selftest
   - prevent a spurious timer interrupt in the NOHZ lowres code
   - a fix for user space interfaces returning the remaining time on
     architectures with CONFIG_TIME_LOW_RES=y
   - a few patches to fix COMPILE_TEST fallout"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/nohz: Set the correct expiry when switching to nohz/lowres mode
  clocksource: Fix dependencies for archs w/o HAS_IOMEM
  clocksource: Select CLKSRC_MMIO where needed
  tick/sched: Hide unused oneshot timer code
  kselftests: timers: Add adjtimex SETOFFSET validity tests
  ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO
  itimers: Handle relative timers with CONFIG_TIME_LOW_RES proper
  posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper
  timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper
  hrtimer: Handle remaining time proper for TIME_LOW_RES
  clockevents/tcb_clksrc: Prevent disabling an already disabled clock

drivers/clocksource/Kconfig

@@ -30,6 +30,8 @@ config CLKSRC_MMIO
 config DIGICOLOR_TIMER
 	bool "Digicolor timer driver" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	depends on HAS_IOMEM
 	help
 	  Enables the support for the digicolor timer driver.
 
@@ -55,6 +57,7 @@ config ARMADA_370_XP_TIMER
 	bool "Armada 370 and XP timer driver" if COMPILE_TEST
 	depends on ARM
 	select CLKSRC_OF
+	select CLKSRC_MMIO
 	help
 	  Enables the support for the Armada 370 and XP timer driver.
 
@@ -76,6 +79,7 @@ config ORION_TIMER
 config SUN4I_TIMER
 	bool "Sun4i timer driver" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	depends on HAS_IOMEM
 	select CLKSRC_MMIO
 	help
 	  Enables support for the Sun4i timer.
@@ -89,6 +93,7 @@ config SUN5I_HSTIMER
 
 config TEGRA_TIMER
 	bool "Tegra timer driver" if COMPILE_TEST
+	select CLKSRC_MMIO
 	depends on ARM
 	help
 	  Enables support for the Tegra driver.
@@ -96,6 +101,7 @@ config TEGRA_TIMER
 config VT8500_TIMER
 	bool "VT8500 timer driver" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	depends on HAS_IOMEM
 	help
 	  Enables support for the VT8500 driver.
 
@@ -131,6 +137,7 @@ config CLKSRC_NOMADIK_MTU_SCHED_CLOCK
 config CLKSRC_DBX500_PRCMU
 	bool "Clocksource PRCMU Timer" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	depends on HAS_IOMEM
 	help
 	  Use the always on PRCMU Timer as clocksource
 
@@ -248,6 +255,7 @@ config CLKSRC_EXYNOS_MCT
 config CLKSRC_SAMSUNG_PWM
 	bool "PWM timer drvier for Samsung S3C, S5P" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	depends on HAS_IOMEM
 	help
 	  This is a new clocksource driver for the PWM timer found in
 	  Samsung S3C, S5P and Exynos SoCs, replacing an earlier driver
@@ -257,12 +265,14 @@ config CLKSRC_SAMSUNG_PWM
 config FSL_FTM_TIMER
 	bool "Freescale FlexTimer Module driver" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	depends on HAS_IOMEM
 	select CLKSRC_MMIO
 	help
 	  Support for Freescale FlexTimer Module (FTM) timer.
 
 config VF_PIT_TIMER
 	bool
+	select CLKSRC_MMIO
 	help
 	  Support for Period Interrupt Timer on Freescale Vybrid Family SoCs.
 
@@ -360,6 +370,7 @@ config CLKSRC_TANGO_XTAL
 config CLKSRC_PXA
 	bool "Clocksource for PXA or SA-11x0 platform" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
+	depends on HAS_IOMEM
 	select CLKSRC_MMIO
 	help
 	  This enables OST0 support available on PXA and SA-11x0
@@ -394,6 +405,7 @@ config CLKSRC_ST_LPC
 	bool "Low power clocksource found in the LPC" if COMPILE_TEST
 	select CLKSRC_OF if OF
 	depends on HAS_IOMEM
+	select CLKSRC_MMIO
 	help
 	  Enable this option to use the Low Power controller timer
 	  as clocksource.

drivers/clocksource/tcb_clksrc.c

@@ -98,7 +98,8 @@ static int tc_shutdown(struct clock_event_device *d)
 
 	__raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
 	__raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
-	clk_disable(tcd->clk);
+	if (!clockevent_state_detached(d))
+		clk_disable(tcd->clk);
 
 	return 0;
 }