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Rafael J. Wysocki authored
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 <mjg@redhat.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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