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.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8effb9b23eec..acae2705e7f6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -672,6 +672,19 @@ void pci_update_current_state(struct pci_dev *dev, pci_power_t state) } } +/** + * pci_power_up - Put the given device into D0 forcibly + * @dev: PCI device to power up + */ +void pci_power_up(struct pci_dev *dev) +{ + if (platform_pci_power_manageable(dev)) + platform_pci_set_power_state(dev, PCI_D0); + + pci_raw_set_power_state(dev, PCI_D0); + pci_update_current_state(dev, PCI_D0); +} + /** * pci_platform_power_transition - Use platform to change device power state * @dev: PCI device to handle. @@ -762,7 +775,7 @@ int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state) { int ret; - if (state < PCI_D0) + if (state <= PCI_D0) return -EINVAL; ret = pci_platform_power_transition(dev, state); /* Power off the bridge may power off the whole hierarchy */ @@ -804,6 +817,10 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) */ return 0; + /* Check if we're already there */ + if (dev->current_state == state) + return 0; + __pci_start_power_transition(dev, state); /* This device is quirked not to be put into D3, so -- cgit v1.2.3-59-g8ed1b