Merge tag 'pm+acpi-3.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:
 "These include two fixes for recent regressions related to ACPI, a
  cpufreq fix for breakage overlooked by a previous fix commit, two
  intel_pstate fixes for stuff added during the 3.13 cycle that need to
  go into -stable, three fixes for older bugs that also are -stable
  candidates, ACPI video blacklist changes related to BIOSes that behave
  in a special way on Windows 8, several build fixes for CONFIG_PM_SLEEP
  unset in ACPI drivers and an ACPI driver cleanup.

  Specifics:

   - Fix for a recent probing regression in the nouveau driver
     introduced by an ACPI change related to the handling of _DSM from
     Jiang Liu.

   - Fix for a dock station sysfs attribute that stopped working
     correctly after recent changes in the ACPI core.

   - cpufreq fix taking care of broken code related to CPU removal and
     overlooked by a previous recent fix in that area.  From Viresh
     Kumar.

   - Two intel_pstate fixes related to Baytrail support added during the
     3.13 cycle (candidates for -stable) from Dirk Brandewie.

   - ACPI video fix removing duplicate brightness values from the _BCL
     table which makes its user space interface behave sanely.  From
     Hans de Goede.

   - Fix for the powernow-k8 cpufreq driver making it initialize its
     per-CPU data structures correctly from Srivatsa S Bhat.

   - Fix for an obscure memory leak in the ACPI PCI interrupt allocation
     code (related to ISA) from Tomasz Nowicki.

   - ACPI video blacklist changes moving several systems that should use
     the native backlight interface instead of the ACPI one from the
     general ACPI _OSI blacklist the the ACPI video driver's blacklist
     where they belong.  This consists of an ACPI video driver update
     from Aaron Lu and a revert of a previous commit adding systems to
     the ACPI _OSI blacklist requested by Takashi Iwai.

   - Several fixes for build issues in ACPI drivers occuring when
     CONFIG_PM_SLEEP is unset from Shuah Khan.

   - Fix for an sscanf() format string in the ACPI Smart Battery
     Subsystem (SBS) driver from Luis G.F"

* tag 'pm+acpi-3.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  intel_pstate: Add support for Baytrail turbo P states
  intel_pstate: Use LFM bus ratio as min ratio/P state
  ACPI / nouveau: fix probing regression related to _DSM
  Revert "ACPI: Blacklist Win8 OSI for some HP laptop 2013 models"
  ACPI / video: Add systems that should favour native backlight interface
  ACPI / video: Filter the _BCL table for duplicate brightness values
  cpufreq: powernow-k8: Initialize per-cpu data-structures properly
  cpufreq: remove sysfs link when a cpu != policy->cpu, is removed
  ACPI / PCI: Fix memory leak in acpi_pci_irq_enable()
  ACPI / dock: Make 'docked' sysfs attribute work as documented
  ACPI / SBS: Fix incorrect sscanf() string
  ACPI / thermal: fix thermal driver compile error when CONFIG_PM_SLEEP is undefined
  ACPI / SBS: fix SBS driver compile error when CONFIG_PM_SLEEP is undefined
  ACPI / fan: fix fan driver compile error when CONFIG_PM_SLEEP is undefined
  ACPI / button: fix button driver compile error when CONFIG_PM_SLEEP is undefined
  ACPI / battery: fix battery driver compile error when CONFIG_PM_SLEEP is undefined
  ACPI / AC: fix AC driver compile error when CONFIG_PM_SLEEP is undefined

1 files changed, 24 insertions, 2 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index 4ef83df2b246..83face3f608f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -106,6 +106,29 @@ static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *
 	return 0;
 }
 
+/*
+ * On some platforms, _DSM(nouveau_op_dsm_muid, func0) has special
+ * requirements on the fourth parameter, so a private implementation
+ * instead of using acpi_check_dsm().
+ */
+static int nouveau_check_optimus_dsm(acpi_handle handle)
+{
+	int result;
+
+	/*
+	 * Function 0 returns a Buffer containing available functions.
+	 * The args parameter is ignored for function 0, so just put 0 in it
+	 */
+	if (nouveau_optimus_dsm(handle, 0, 0, &result))
+		return 0;
+
+	/*
+	 * ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported.
+	 * If the n-th bit is enabled, function n is supported
+	 */
+	return result & 1 && result & (1 << NOUVEAU_DSM_OPTIMUS_CAPS);
+}
+
 static int nouveau_dsm(acpi_handle handle, int func, int arg)
 {
 	int ret = 0;
@@ -207,8 +230,7 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev)
 			   1 << NOUVEAU_DSM_POWER))
 		retval |= NOUVEAU_DSM_HAS_MUX;
 
-	if (acpi_check_dsm(dhandle, nouveau_op_dsm_muid, 0x00000100,
-			   1 << NOUVEAU_DSM_OPTIMUS_CAPS))
+	if (nouveau_check_optimus_dsm(dhandle))
 		retval |= NOUVEAU_DSM_HAS_OPT;
 
 	if (retval & NOUVEAU_DSM_HAS_OPT) {