Applied to acpi-test
thanks,
-Len
On Thursday 26 April 2007 03:03, akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> From: Venki Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
>
> Prevent hang on x86-64, when ACPI processor driver is added as a module on
> a system that does not support C-states.
>
> x86-64 expects all idle handlers to enable interrupts before returning from
> idle handler. This is due to enter_idle(), exit_idle() races. Make
> cpuidle_idle_call() confirm to this when there is no pm_idle_old.
>
> Also, cpuidle look at the return values of attch_driver() and set
> current_driver to NULL if attach fails on all CPUs.
>
> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> drivers/cpuidle/cpuidle.c | 2 ++
> drivers/cpuidle/driver.c | 15 ++++++++++++---
> 2 files changed, 14 insertions(+), 3 deletions(-)
>
> diff -puN drivers/cpuidle/cpuidle.c~cpuidle-hang-fix drivers/cpuidle/cpuidle.c
> --- a/drivers/cpuidle/cpuidle.c~cpuidle-hang-fix
> +++ a/drivers/cpuidle/cpuidle.c
> @@ -43,6 +43,8 @@ static void cpuidle_idle_call(void)
> if (dev->status != CPUIDLE_STATUS_DOIDLE) {
> if (pm_idle_old)
> pm_idle_old();
> + else
> + local_irq_enable();
> return;
> }
>
> diff -puN drivers/cpuidle/driver.c~cpuidle-hang-fix drivers/cpuidle/driver.c
> --- a/drivers/cpuidle/driver.c~cpuidle-hang-fix
> +++ a/drivers/cpuidle/driver.c
> @@ -107,11 +107,20 @@ int cpuidle_switch_driver(struct cpuidle
> cpuidle_curr_driver = drv;
>
> if (drv) {
> + int ret = 1;
> list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
> - cpuidle_attach_driver(dev);
> - if (cpuidle_curr_governor)
> + if (cpuidle_attach_driver(dev) == 0)
> + ret = 0;
> +
> + /* If attach on all devices fail, switch to NULL driver */
> + if (ret)
> + cpuidle_curr_driver = NULL;
> +
> + if (cpuidle_curr_driver && cpuidle_curr_governor) {
> + printk(KERN_INFO "cpuidle: using driver %s\n",
> + drv->name);
> cpuidle_install_idle_handler();
> - printk(KERN_INFO "cpuidle: using driver %s\n", drv->name);
> + }
> }
>
> return 0;
> _
> -
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