From: Rafael J. Wysocki <rjw@xxxxxxx> The wakeup.prepared flag is used for marking devices that have the wake-up power already enabled, so that the wake-up power is not enabled twice in a row for the same device. This assumes, however, that device wake-up power will only be enabled once, while the device is being prepared for a system-wide sleep transition, and the second attempt is made by acpi_enable_wakeup_device_prep(). With the upcoming PCI wake-up rework this assumption will not hold any more for PCI bridges and the root bridge whose wake-up power may be enabled as a result of wake-up enable propagation from other devices (eg. add-on devices that are not associated with any GPEs). Thus, there may be many attempts to enable wake-up power on a PCI bridge or the root bridge during a system power state transition and it's better to replace wakeup.prepared with a reference counter. Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> --- drivers/acpi/power.c | 58 ++++++++++++++++++++++++++++-------------------- drivers/acpi/scan.c | 1 drivers/acpi/wakeup.c | 4 +-- include/acpi/acpi_bus.h | 2 - 4 files changed, 39 insertions(+), 26 deletions(-) Index: linux-2.6/drivers/acpi/scan.c =================================================================== --- linux-2.6.orig/drivers/acpi/scan.c +++ linux-2.6/drivers/acpi/scan.c @@ -781,6 +781,7 @@ static int acpi_bus_get_wakeup_device_fl kfree(buffer.pointer); device->wakeup.flags.valid = 1; + device->wakeup.prepare_count = 0; /* Call _PSW/_DSW object to disable its ability to wake the sleeping * system for the ACPI device with the _PRW object. * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW. Index: linux-2.6/include/acpi/acpi_bus.h =================================================================== --- linux-2.6.orig/include/acpi/acpi_bus.h +++ linux-2.6/include/acpi/acpi_bus.h @@ -248,7 +248,6 @@ struct acpi_device_perf { /* Wakeup Management */ struct acpi_device_wakeup_flags { u8 valid:1; /* Can successfully enable wakeup? */ - u8 prepared:1; /* Has the wake-up capability been enabled? */ u8 run_wake:1; /* Run-Wake GPE devices */ }; @@ -263,6 +262,7 @@ struct acpi_device_wakeup { struct acpi_handle_list resources; struct acpi_device_wakeup_state state; struct acpi_device_wakeup_flags flags; + int prepare_count; }; /* Device */ Index: linux-2.6/drivers/acpi/power.c =================================================================== --- linux-2.6.orig/drivers/acpi/power.c +++ linux-2.6/drivers/acpi/power.c @@ -44,6 +44,8 @@ #include <acpi/acpi_bus.h> #include <acpi/acpi_drivers.h> +#include "sleep.h" + #define _COMPONENT ACPI_POWER_COMPONENT ACPI_MODULE_NAME("power"); #define ACPI_POWER_CLASS "power_resource" @@ -361,17 +363,15 @@ int acpi_device_sleep_wake(struct acpi_d */ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state) { - int i, err; + int i, err = 0; if (!dev || !dev->wakeup.flags.valid) return -EINVAL; - /* - * Do not execute the code below twice in a row without calling - * acpi_disable_wakeup_device_power() in between for the same device - */ - if (dev->wakeup.flags.prepared) - return 0; + mutex_lock(&acpi_device_lock); + + if (dev->wakeup.prepare_count++) + goto out; /* Open power resource */ for (i = 0; i < dev->wakeup.resources.count; i++) { @@ -379,7 +379,8 @@ int acpi_enable_wakeup_device_power(stru if (ret) { printk(KERN_ERR PREFIX "Transition power state\n"); dev->wakeup.flags.valid = 0; - return -ENODEV; + err = -ENODEV; + goto err_out; } } @@ -388,9 +389,13 @@ int acpi_enable_wakeup_device_power(stru * in arbitrary power state afterwards. */ err = acpi_device_sleep_wake(dev, 1, sleep_state, 3); - if (!err) - dev->wakeup.flags.prepared = 1; + err_out: + if (err) + dev->wakeup.prepare_count = 0; + + out: + mutex_unlock(&acpi_device_lock); return err; } @@ -402,35 +407,42 @@ int acpi_enable_wakeup_device_power(stru */ int acpi_disable_wakeup_device_power(struct acpi_device *dev) { - int i, ret; + int i, err = 0; if (!dev || !dev->wakeup.flags.valid) return -EINVAL; + mutex_lock(&acpi_device_lock); + + if (--dev->wakeup.prepare_count > 0) + goto out; + /* - * Do not execute the code below twice in a row without calling - * acpi_enable_wakeup_device_power() in between for the same device + * Executing the code below even if prepare_count is already zero when + * the function is called may be useful, for example for initialisation. */ - if (!dev->wakeup.flags.prepared) - return 0; + if (dev->wakeup.prepare_count < 0) + dev->wakeup.prepare_count = 0; - dev->wakeup.flags.prepared = 0; - - ret = acpi_device_sleep_wake(dev, 0, 0, 0); - if (ret) - return ret; + err = acpi_device_sleep_wake(dev, 0, 0, 0); + if (err) + goto out; /* Close power resource */ for (i = 0; i < dev->wakeup.resources.count; i++) { - ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev); + int ret = acpi_power_off_device( + dev->wakeup.resources.handles[i], dev); if (ret) { printk(KERN_ERR PREFIX "Transition power state\n"); dev->wakeup.flags.valid = 0; - return -ENODEV; + err = -ENODEV; + goto out; } } - return ret; + out: + mutex_unlock(&acpi_device_lock); + return err; } /* -------------------------------------------------------------------------- Index: linux-2.6/drivers/acpi/wakeup.c =================================================================== --- linux-2.6.orig/drivers/acpi/wakeup.c +++ linux-2.6/drivers/acpi/wakeup.c @@ -68,7 +68,7 @@ void acpi_enable_wakeup_device(u8 sleep_ /* If users want to disable run-wake GPE, * we only disable it for wake and leave it for runtime */ - if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared) + if ((!dev->wakeup.state.enabled && !dev->wakeup.prepare_count) || sleep_state > (u32) dev->wakeup.sleep_state) { if (dev->wakeup.flags.run_wake) { /* set_gpe_type will disable GPE, leave it like that */ @@ -100,7 +100,7 @@ void acpi_disable_wakeup_device(u8 sleep if (!dev->wakeup.flags.valid) continue; - if ((!dev->wakeup.state.enabled && !dev->wakeup.flags.prepared) + if ((!dev->wakeup.state.enabled && !dev->wakeup.prepare_count) || sleep_state > (u32) dev->wakeup.sleep_state) { if (dev->wakeup.flags.run_wake) { acpi_set_gpe_type(dev->wakeup.gpe_device, _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm