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| author | Rafael J. Wysocki <rjw@sisk.pl> | 2012-07-06 01:20:00 +0400 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2012-07-06 01:20:00 +0400 |
| commit | db288c9c5f9db45610dab3940377625132b4af41 (patch) | |
| tree | ef859024757b4b468eb33aa5d9f879aa28fdd754 /drivers/pci/pci.c | |
| parent | 448bd857d48e69b33ef323739dc6d8ca20d4cda7 (diff) | |
| download | linux-db288c9c5f9db45610dab3940377625132b4af41.tar.xz | |
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 <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 19 |
1 files changed, 18 insertions, 1 deletions
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 @@ -673,6 +673,19 @@ 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. * @state: State to put the device into. @@ -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 |