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authorRafael J. Wysocki <rjw@sisk.pl>2012-07-05 15:20:00 -0600
committerBjorn Helgaas <bhelgaas@google.com>2012-07-05 15:20:00 -0600
commitdb288c9c5f9db45610dab3940377625132b4af41 (patch)
treeef859024757b4b468eb33aa5d9f879aa28fdd754 /drivers/pci
parent448bd857d48e69b33ef323739dc6d8ca20d4cda7 (diff)
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')
-rw-r--r--drivers/pci/pci-driver.c14
-rw-r--r--drivers/pci/pci.c19
-rw-r--r--drivers/pci/pci.h1
3 files changed, 27 insertions, 7 deletions
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);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8effb9b23ee..acae2705e7f 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
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 5cd3dce7a24..331857855eb 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -67,6 +67,7 @@ struct pci_platform_pm_ops {
extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
extern void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
+extern void pci_power_up(struct pci_dev *dev);
extern void pci_disable_enabled_device(struct pci_dev *dev);
extern int pci_finish_runtime_suspend(struct pci_dev *dev);
extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign);