On Tuesday, June 13, 2017 10:52:52 AM Greg KH wrote: > On Mon, Jun 12, 2017 at 10:49:40PM +0200, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > > > > hcd_pci_resume_noirq() used as a universal _resume_noirq handler for > > PCI USB controllers calls pci_back_from_sleep() which is unnecessary > > and may become problematic. > > > > It is unnecessary, because the PCI bus type carries out post-suspend > > cleanup of all PCI devices during resume and that covers all things > > done by the pci_back_from_sleep(). There is no reason why USB cannot > > follow all of the other PCI devices in that respect. > > > > It will become problematic after subsequent changes that make it > > possible to go back to sleep again after executing dpm_resume_noirq() > > if no valid system wakeup events have been detected at that point. > > Namely, calling pci_back_from_sleep() at the _resume_noirq stage > > will cause the wakeup status of the devices in question to be cleared > > and if any of them has triggered system wakeup, that event may be > > missed then. > > > > For the above reasons, drop the pci_back_from_sleep() invocation > > from hcd_pci_resume_noirq(). > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > > Acked-by: Alan Stern <st...@rowland.harvard.edu> > > Acked-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
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