From db288c9c5f9db45610dab3940377625132b4af41 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 5 Jul 2012 15:20:00 -0600 Subject: PCI / PM: restore the original behavior of pci_set_power_state() Commit cc2893b6 (PCI: Ensure we re-enable devices on resume) addressed the problem with USB not being powered after resume on recent Lenovo machines, but it did that in a suboptimal way. Namely, it should have changed the relevant code paths only, which are pci_pm_resume_noirq() and pci_pm_restore_noirq() supposed to restore the device's power and standard configuration registers after system resume from suspend or hibernation. Instead, however, it modified pci_set_power_state() which is executed in several other situations too. That resulted in some undesirable effects, like attempting to change a device's power state in the same way multiple times in a row (up to as many as 4 times in a row in the snd_hda_intel driver). Fix the bug addressed by commit cc2893b6 in an alternative way, by forcibly powering up all devices in pci_pm_default_resume_early(), which is called by pci_pm_resume_noirq() and pci_pm_restore_noirq() to restore the device's power and standard configuration registers, and modifying pci_pm_runtime_resume() to avoid the forcible power-up if not necessary. Then, revert the changes made by commit cc2893b6 to make the confusion introduced by it go away. Acked-by: Matthew Garrett Signed-off-by: Rafael J. Wysocki Signed-off-by: Bjorn Helgaas --- drivers/pci/pci-driver.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'drivers/pci/pci-driver.c') diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index ca2e4c79a58..1dd1d9dfa17 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -459,16 +459,17 @@ static int pci_restore_standard_config(struct pci_dev *pci_dev) return 0; } +#endif + +#ifdef CONFIG_PM_SLEEP + static void pci_pm_default_resume_early(struct pci_dev *pci_dev) { - pci_restore_standard_config(pci_dev); + pci_power_up(pci_dev); + pci_restore_state(pci_dev); pci_fixup_device(pci_fixup_resume_early, pci_dev); } -#endif - -#ifdef CONFIG_PM_SLEEP - /* * Default "suspend" method for devices that have no driver provided suspend, * or not even a driver at all (second part). @@ -1054,7 +1055,8 @@ static int pci_pm_runtime_resume(struct device *dev) if (!pm || !pm->runtime_resume) return -ENOSYS; - pci_pm_default_resume_early(pci_dev); + pci_restore_standard_config(pci_dev); + pci_fixup_device(pci_fixup_resume_early, pci_dev); __pci_enable_wake(pci_dev, PCI_D0, true, false); pci_fixup_device(pci_fixup_resume, pci_dev); -- cgit v1.2.3