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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2008-05-19 19:09:27 -0400
committerLen Brown <len.brown@intel.com>2008-06-11 19:13:45 -0400
commitdcb84f335bee9c9a7781cfc5d74492dccaf066d2 (patch)
treee24d4ca7df49b2a87862aa69c09d21ad45a024b7 /drivers/acpi/processor_idle.c
parente1094bfa26e5e94af2fea79e004614dbce42b008 (diff)
downloadlinux-dcb84f335bee9c9a7781cfc5d74492dccaf066d2.tar.bz2
cpuidle acpi driver: fix oops on AC<->DC
cpuidle and acpi driver interaction bug with the way cpuidle_register_driver() is called. Due to this bug, there will be oops on AC<->DC on some systems, where they support C-states in one DC and not in AC. The current code does ON BOOT: Look at CST and other C-state info to see whether more than C1 is supported. If it is, then acpi processor_idle does a cpuidle_register_driver() call, which internally enables the device. ON CST change notification (AC<->DC) and on suspend-resume: acpi driver temporarily disables device, updates the device with any new C-states, and reenables the device. The problem is is on boot, there are no C2, C3 states supported and we skip the register. Later on AC<->DC, we may get a CST notification and we try to reevaluate CST and enabled the device, without actually registering it. This causes breakage as we try to create /sys fs sub directory, without the parent directory which is created at register time. Thanks to Sanjeev for reporting the problem here. http://bugzilla.kernel.org/show_bug.cgi?id=10394 Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 2dd2c1f3a01c..556ee1585192 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1669,6 +1669,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
return -EINVAL;
}
+ dev->cpu = pr->id;
for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
dev->states[i].name[0] = '\0';
dev->states[i].desc[0] = '\0';
@@ -1738,7 +1739,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
int acpi_processor_cst_has_changed(struct acpi_processor *pr)
{
- int ret;
+ int ret = 0;
if (boot_option_idle_override)
return 0;
@@ -1756,8 +1757,10 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
cpuidle_pause_and_lock();
cpuidle_disable_device(&pr->power.dev);
acpi_processor_get_power_info(pr);
- acpi_processor_setup_cpuidle(pr);
- ret = cpuidle_enable_device(&pr->power.dev);
+ if (pr->flags.power) {
+ acpi_processor_setup_cpuidle(pr);
+ ret = cpuidle_enable_device(&pr->power.dev);
+ }
cpuidle_resume_and_unlock();
return ret;
@@ -1813,7 +1816,6 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
if (pr->flags.power) {
#ifdef CONFIG_CPU_IDLE
acpi_processor_setup_cpuidle(pr);
- pr->power.dev.cpu = pr->id;
if (cpuidle_register_device(&pr->power.dev))
return -EIO;
#endif
@@ -1850,8 +1852,7 @@ int acpi_processor_power_exit(struct acpi_processor *pr,
return 0;
#ifdef CONFIG_CPU_IDLE
- if (pr->flags.power)
- cpuidle_unregister_device(&pr->power.dev);
+ cpuidle_unregister_device(&pr->power.dev);
#endif
pr->flags.power_setup_done = 0;