Merge tag 'char-misc-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver patches from Greg KH:
 "Here's the "big" char/misc driver update for 4.3-rc1.

  Not much really interesting here, just a number of little changes all
  over the place, and some nice consolidation of the nvmem drivers to a
  common framework.  As usual, the mei drivers stand out as the largest
  "churn" to handle new devices and features in their hardware.

  All have been in linux-next for a while with no issues"

* tag 'char-misc-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits)
  auxdisplay: ks0108: initialize local parport variable
  extcon: palmas: Fix build break due to devm_gpiod_get_optional API change
  extcon: palmas: Support GPIO based USB ID detection
  extcon: Fix signedness bugs about break error handling
  extcon: Drop owner assignment from i2c_driver
  extcon: arizona: Simplify pdata symantics for micd_dbtime
  extcon: arizona: Declare 3-pole jack if we detect open circuit on mic
  extcon: Add exception handling to prevent the NULL pointer access
  extcon: arizona: Ensure variables are set for headphone detection
  extcon: arizona: Use gpiod inteface to handle micd_pol_gpio gpio
  extcon: arizona: Add basic microphone detection DT/ACPI bindings
  extcon: arizona: Update to use the new device properties API
  extcon: palmas: Remove the mutually_exclusive array
  extcon: Remove optional print_state() function pointer of struct extcon_dev
  extcon: Remove duplicate header file in extcon.h
  extcon: max77843: Clear IRQ bits state before request IRQ
  toshiba laptop: replace ioremap_cache with ioremap
  misc: eeprom: max6875: clean up max6875_read()
  misc: eeprom: clean up eeprom_read()
  misc: eeprom: 93xx46: clean up eeprom_93xx46_bin_read/write
  ...

1 files changed, 15 insertions, 9 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5644ec5582b9..718ea76b78ba 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -191,17 +191,18 @@ void cpu_hotplug_done(void)
 void cpu_hotplug_disable(void)
 {
 	cpu_maps_update_begin();
-	cpu_hotplug_disabled = 1;
+	cpu_hotplug_disabled++;
 	cpu_maps_update_done();
 }
+EXPORT_SYMBOL_GPL(cpu_hotplug_disable);
 
 void cpu_hotplug_enable(void)
 {
 	cpu_maps_update_begin();
-	cpu_hotplug_disabled = 0;
+	WARN_ON(--cpu_hotplug_disabled < 0);
 	cpu_maps_update_done();
 }
-
+EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
 #endif	/* CONFIG_HOTPLUG_CPU */
 
 /* Need to know about CPUs going up/down? */
@@ -608,13 +609,18 @@ int disable_nonboot_cpus(void)
 		}
 	}
 
-	if (!error) {
+	if (!error)
 		BUG_ON(num_online_cpus() > 1);
-		/* Make sure the CPUs won't be enabled by someone else */
-		cpu_hotplug_disabled = 1;
-	} else {
+	else
 		pr_err("Non-boot CPUs are not disabled\n");
-	}
+
+	/*
+	 * Make sure the CPUs won't be enabled by someone else. We need to do
+	 * this even in case of failure as all disable_nonboot_cpus() users are
+	 * supposed to do enable_nonboot_cpus() on the failure path.
+	 */
+	cpu_hotplug_disabled++;
+
 	cpu_maps_update_done();
 	return error;
 }
@@ -633,7 +639,7 @@ void __ref enable_nonboot_cpus(void)
 
 	/* Allow everyone to use the CPU hotplug again */
 	cpu_maps_update_begin();
-	cpu_hotplug_disabled = 0;
+	WARN_ON(--cpu_hotplug_disabled < 0);
 	if (cpumask_empty(frozen_cpus))
 		goto out;