From cb8f51bdadb7969139c2e39c2defd4cde98c1ea8 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 8 Feb 2011 23:26:02 +0100 Subject: PM: Do not create wakeup sysfs files for devices that cannot wake up Currently, wakeup sysfs attributes are created for all devices, regardless of whether or not they are wakeup-capable. This is excessive and complicates wakeup device identification from user space (i.e. to identify wakeup-capable devices user space has to read /sys/devices/.../power/wakeup for all devices and see if they are not empty). Fix this issue by avoiding to create wakeup sysfs files for devices that cannot wake up the system from sleep states (i.e. whose power.can_wakeup flags are unset during registration) and modify device_set_wakeup_capable() so that it adds (or removes) the relevant sysfs attributes if a device's wakeup capability status is changed. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/wakeup.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'drivers/base/power/wakeup.c') diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index 82836383997f..4573c83df6dd 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -241,6 +241,35 @@ int device_wakeup_disable(struct device *dev) } EXPORT_SYMBOL_GPL(device_wakeup_disable); +/** + * device_set_wakeup_capable - Set/reset device wakeup capability flag. + * @dev: Device to handle. + * @capable: Whether or not @dev is capable of waking up the system from sleep. + * + * If @capable is set, set the @dev's power.can_wakeup flag and add its + * wakeup-related attributes to sysfs. Otherwise, unset the @dev's + * power.can_wakeup flag and remove its wakeup-related attributes from sysfs. + * + * This function may sleep and it can't be called from any context where + * sleeping is not allowed. + */ +void device_set_wakeup_capable(struct device *dev, bool capable) +{ + if (!!dev->power.can_wakeup == !!capable) + return; + + if (device_is_registered(dev)) { + if (capable) { + if (wakeup_sysfs_add(dev)) + return; + } else { + wakeup_sysfs_remove(dev); + } + } + dev->power.can_wakeup = capable; +} +EXPORT_SYMBOL_GPL(device_set_wakeup_capable); + /** * device_init_wakeup - Device wakeup initialization. * @dev: Device to handle. -- cgit v1.2.2