On Wed, 2 Jan 2008 00:32:44 +0100 "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > Some device drivers register CPU hotplug notifiers and use them to destroy > device objects when removing the corresponding CPUs and to create these objects > when adding the CPUs back. > > Unfortunately, this is not the right thing to do during suspend/hibernation, > since in that cases the CPU hotplug notifiers are called after suspending > devices and before resuming them, so the operations in question are carried > out on the objects representing suspended devices which shouldn't be > unregistered behing the PM core's back. __Although right now it usually doesn't > lead to any practical complications, it will predictably deadlock if > gregkh-driver-pm-acquire-device-locks-prior-to-suspending.patch is applied. > > The solution is to prevent drivers from removing/adding devices from within > CPU hotplug notifiers during suspend/hibernation using the FROZEN bit > in the notifier's action argument. However, this has to be done with care, > since the devices objects related to the nonboot CPUs that failed to go online > during resume should not be present in the system. For this reason, it seems > reasonable to introduce a mechanism allowing drivers to ask the PM core to > remove device objects corresponding to suspended devices on their behalf. > > The first patch in the series introduces such a mechanism. The remaining three > patches modify the MSR, x86-64 MCE and cpuid drivers in accordance with the > above approach. These patches are a preresuisite to gregkh-driver-pm-acquire-device-locks-prior-to-suspending.patch and its later fixed-up versions. So what I have now is revert-gregkh-driver-pm-acquire-device-locks-prior-to-suspending.patch pm-introduce-destroy_suspended_device.patch pm-do-not-destroy-create-devices-while-suspended-in-msrc-rev-2.patch pm-do-not-destroy-create-devices-while-suspended-in-mce_64c.patch pm-do-not-destroy-create-devices-while-suspended-in-cpuidc.patch pm-acquire-device-locks-on-suspend-rev-3.patch pm-acquire-device-locks-on-suspend-rev-3-checkpatch-fixes.patch pm-acquire-device-locks-on-suspend-rev-3-checkpatch-fixes-2.patch So what needs to happen in Greg's tree is a) drop the old gregkh-driver-pm-acquire-device-locks-prior-to-suspending.patch b) apply these four patches c) apply the new pm-acquire-device-locks-on-suspend-rev-3.patch (and its fixups) - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
