Merge tag 'pm+acpi-3.15-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management fixes and updates from Rafael Wysocki:
 "This is PM and ACPI material that has emerged over the last two weeks
  and one fix for a CPU hotplug regression introduced by the recent CPU
  hotplug notifiers registration series.

  Included are intel_idle and turbostat updates from Len Brown (these
  have been in linux-next for quite some time), a new cpufreq driver for
  powernv (that might spend some more time in linux-next, but BenH was
  asking me so nicely to push it for 3.15 that I couldn't resist), some
  cpufreq fixes and cleanups (including fixes for some silly breakage in
  a couple of cpufreq drivers introduced during the 3.14 cycle),
  assorted ACPI cleanups, wakeup framework documentation fixes, a new
  sysfs attribute for cpuidle and a new command line argument for power
  domains diagnostics.

  Specifics:

   - Fix for a recently introduced CPU hotplug regression in ARM KVM
     from Ming Lei.

   - Fixes for breakage in the at32ap, loongson2_cpufreq, and unicore32
     cpufreq drivers introduced during the 3.14 cycle (-stable material)
     from Chen Gang and Viresh Kumar.

   - New powernv cpufreq driver from Vaidyanathan Srinivasan, with bits
     from Gautham R Shenoy and Srivatsa S Bhat.

   - Exynos cpufreq driver fix preventing it from being included into
     multiplatform builds that aren't supported by it from Sachin Kamat.

   - cpufreq cleanups related to the usage of the driver_data field in
     struct cpufreq_frequency_table from Viresh Kumar.

   - cpufreq ppc driver cleanup from Sachin Kamat.

   - Intel BayTrail support for intel_idle and ACPI idle from Len Brown.

   - Intel CPU model 54 (Atom N2000 series) support for intel_idle from
     Jan Kiszka.

   - intel_idle fix for Intel Ivy Town residency targets from Len Brown.

   - turbostat updates (Intel Broadwell support and output cleanups)
     from Len Brown.

   - New cpuidle sysfs attribute for exporting C-states' target
     residency information to user space from Daniel Lezcano.

   - New kernel command line argument to prevent power domains enabled
     by the bootloader from being turned off even if they are not in use
     (for diagnostics purposes) from Tushar Behera.

   - Fixes for wakeup sysfs attributes documentation from Geert
     Uytterhoeven.

   - New ACPI video blacklist entry for ThinkPad Helix from Stephen
     Chandler Paul.

   - Assorted ACPI cleanups and a Kconfig help update from Jonghwan
     Choi, Zhihui Zhang, Hanjun Guo"

* tag 'pm+acpi-3.15-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (28 commits)
  ACPI: Update the ACPI spec information in Kconfig
  arm, kvm: fix double lock on cpu_add_remove_lock
  cpuidle: sysfs: Export target residency information
  cpufreq: ppc: Remove duplicate inclusion of fsl_soc.h
  cpufreq: create another field .flags in cpufreq_frequency_table
  cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table
  cpufreq: don't print value of .driver_data from core
  cpufreq: ia64: don't set .driver_data to index
  cpufreq: powernv: Select CPUFreq related Kconfig options for powernv
  cpufreq: powernv: Use cpufreq_frequency_table.driver_data to store pstate ids
  cpufreq: powernv: cpufreq driver for powernv platform
  cpufreq: at32ap: don't declare local variable as static
  cpufreq: loongson2_cpufreq: don't declare local variable as static
  cpufreq: unicore32: fix typo issue for 'clk'
  cpufreq: exynos: Disable on multiplatform build
  PM / wakeup: Correct presence vs. emptiness of wakeup_* attributes
  PM / domains: Add pd_ignore_unused to keep power domains enabled
  ACPI / dock: Drop dock_device_ids[] table
  ACPI / video: Favor native backlight interface for ThinkPad Helix
  ACPI / thermal: Fix wrong variable usage in debug statement
  ...

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index e69182fd01c..4b28159e042 100644
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -87,7 +87,9 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx)
 	num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK;
 
 	retval = 0;
-	if (num_cstate_subtype < (cx->address & MWAIT_SUBSTATE_MASK)) {
+	/* If the HW does not support any sub-states in this C-state */
+	if (num_cstate_subtype == 0) {
+		pr_warn(FW_BUG "ACPI MWAIT C-state 0x%x not supported by HW (0x%x)\n", cx->address, edx_part);
 		retval = -1;
 		goto out;
 	}