On Thursday, July 24, 2014 03:42:41 PM Peter Zijlstra wrote: > On Wed, Jul 23, 2014 at 10:46:26PM +0200, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > The "freeze" sleep state, also known as suspend-to-idle, is entered > > without taking nonboot CPUs offline, right after devices have been > > suspended. It works by waiting for at least one wakeup source object > > to become "active" as a result of handling a hardware interrupt. > > > > Of course, interrupts supposed to be able to wake up the system from > > suspend-to-idle cannot be disabled by suspend_device_irqs() and their > > interrupt handlers must be able to cope with interrupts coming after > > all devices have been suspended. In that case, they only need to > > call __pm_wakeup_event() for a single wakeup source object without > > trying to access hardware (that will be resumed later as part of > > the subsequent system resume). > > > > Make PCIe PME interrupts work this way. > > > > Register an additional wakeup source object for each PCIe PME > > service device. That object will be used to generate wakeups from > > suspend-to-idle. > > > > Add IRQF_NO_SUSPEND to PME interrupt flags. This will make > > suspend_device_irqs() to ignore PME interrupts, but that's OK, > > because the PME interrupt handler is suspend-aware anyway and > > can cope with interrupts coming during system suspend-resume. > > > > For each PCIe port with PME service during the "prepare" phase of > > system suspend walk the bus below it and see if any devices on that > > bus are configured for wakeup. If so, mark the port as one that can > > be used for system wakeup signaling and handle it differenty going > > forward. > > > > Namely, while suspending its PME service, do not disable the PME > > interrupt, but only set a "suspended" flag for the PME service to > > make the interrupt handler behave in a special way, which is to call > > __pm_wakeup_event() with the service's wakeup source object as the > > first argument whenever the interrupt is triggered. > > > > The "suspended" flag is cleared while resuming the PME service and > > the "wakeup" flag is cleared at the "complete" stage of system > > resume. > > > > This change allows Wake-on-LAN to be used for wakeup from > > suspend-to-idle on my MSI Wind tesbed netbook. > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > --- > > > - ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv); > > + ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED | IRQF_NO_SUSPEND, > > + "PCIe PME", srv); > > So with this patch on: > > http://marc.info/?l=linux-kernel&m=140620918218199 ACK for this one (already sent in that thread). > This will not work on my machine, because aerdrv is requesting the same > irq. AER is PCIe error reporting service. > Now I've not a f'cking clue what aerdrv is, and whether it too wants > NO_SUSPEND on or not. > > But if I make it also request NO_SUSPEND it all starts working. I think we should make all PCIe port services (there may be hotplug too) use IRQF_NO_SUSPEND which will solve this particular problem, but there's more to that (for example, ACPI SCI which in theory may be shared). I guess it's time to revisit that thing, but that's a separate issue, of course. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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