diff options
| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2008-05-20 03:09:27 +0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-06-12 03:13:45 +0400 |
| commit | dcb84f335bee9c9a7781cfc5d74492dccaf066d2 (patch) | |
| tree | e24d4ca7df49b2a87862aa69c09d21ad45a024b7 /drivers/acpi/processor_idle.c | |
| parent | e1094bfa26e5e94af2fea79e004614dbce42b008 (diff) | |
| download | linux-dcb84f335bee9c9a7781cfc5d74492dccaf066d2.tar.xz | |
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.c | 13 |
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; |