On Thu, 14 Dec 2017, Rafael J. Wysocki wrote: > The problem here is that pci_pm_thaw_noirq() calls pci_restore_state() which > in fact requires the device to be in D0, so the caller should put it into > D0 instead of trying to "update" its power state. > > [Note that the PCI layer doesn't put devices into low-power states during the > hibernation's "freeze" transition, but drivers can legitimately do that in > their "freeze" callbacks which was overlooked in that code and that's what > i915 does.] > > So IMO what we need is the change below. I'm going to test it shortly, > but please give it a go too. So now this looks more reasonable: irq_migrate_all_off_this_cpu: Mask 125 pci_msi_mask_irq+0x0/0x10 __pci_write_msi_msg: 0000:00:02.0 00000000fee0100c 0000412a __pci_write_msi_msg: Not written ... device_pm_callback_start: i915 0000:00:02.0, parent: pci0000:00, noirq bus [thaw] pci_pm_thaw_noirq <-dpm_run_callback __pci_write_msi_msg: 0000:00:02.0 00000000fee0100c 0000412a device_pm_callback_end: i915 0000:00:02.0, err=0 ... resume_irqs: Resume 125 ... irq_handler_entry: irq=125 name=i915 Thanks, tglx > --- > drivers/pci/pci-driver.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -1027,7 +1027,12 @@ static int pci_pm_thaw_noirq(struct devi > if (pci_has_legacy_pm_support(pci_dev)) > return pci_legacy_resume_early(dev); > > - pci_update_current_state(pci_dev, PCI_D0); > + /* > + * pci_restore_state() requires the device to be in D0 (because of MSI > + * restoration among other things), so force it into D0 in case the > + * driver's "freeze" callbacks put it into a low-power state directly. > + */ > + pci_set_power_state(pci_dev, PCI_D0); > pci_restore_state(pci_dev); > > if (drv && drv->pm && drv->pm->thaw_noirq) > >
