On Sun, 28 Oct 2012, Ulf Hansson wrote: > On 28 October 2012 20:52, Linus Walleij <linus.wall...@linaro.org> wrote: > > On Sat, Oct 27, 2012 at 11:46 PM, Mark Brown > > <broo...@opensource.wolfsonmicro.com> wrote: > >> On Fri, Oct 05, 2012 at 09:43:32AM +0200, Ulf Hansson wrote: > >> > >>> To be able to deactivate resourses in suspend, the resourses must > >>> first be surely active. This is done with a pm_runtime_get_sync. > >>> Once the resourses are restored to active state again in resume, > >>> the runtime pm usage count can be decreased with a pm_runtime_put. > >> > >> The PM core will ensure devices are runtime resumed before we enter > >> suspend precisely due to this sort of issue. > > > > I asked the very same question to Ulf (in speech, sorry > > so you couldn't see it...) > > > > So I guess we are talking about drivers/base/main.c > > > > in device_prepare() > > pm_runtime_get_noresume() is called > > This will increase the "usage_counter" for the device. It will not > "runtime_resume" the device, though it will prevent it from being > "runtime_suspended".
Indeed. The PM core does _not_ insure that devices are runtime resumed before going into system suspend. Some subsystems may do this (the PCI subsystem does, for example -- see drivers/pci/pci-driver.c:pci_pm_prepare()), but the PM core doesn't. Alan Stern ------------------------------------------------------------------------------ WINDOWS 8 is here. Millions of people. Your app in 30 days. Visit The Windows 8 Center at Sourceforge for all your go to resources. http://windows8center.sourceforge.net/ join-generation-app-and-make-money-coding-fast/ _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
