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USB/PCI: Fix resume breakage of controllers behind cardbus bridges
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If a USB PCI controller is behind a cardbus bridge, we are trying to
restore its configuration registers too early, before the cardbus
bridge is operational.  To fix this, call pci_restore_state() from
usb_hcd_pci_resume() and remove usb_hcd_pci_resume_early() which is
no longer necessary (the configuration spaces of USB controllers that
are not behind cardbus bridges will be restored by the PCI PM core
with interrupts disabled anyway).

This patch fixes the regression from 2.6.28 tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=12659

[ Side note: the proper long-term fix is probably to just force the
  unplug event at suspend time instead of doing a plug/unplug at resume
  time, but this patch is fine regardless  - Linus ]

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Rafael J. Wysocki authored and Linus Torvalds committed Feb 18, 2009
1 parent e78ac4b commit 3494252
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Showing 5 changed files with 2 additions and 17 deletions.
15 changes: 2 additions & 13 deletions drivers/usb/core/hcd-pci.c
Original file line number Diff line number Diff line change
Expand Up @@ -297,19 +297,6 @@ int usb_hcd_pci_suspend(struct pci_dev *dev, pm_message_t message)
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_suspend);

/**
* usb_hcd_pci_resume_early - resume a PCI-based HCD before IRQs are enabled
* @dev: USB Host Controller being resumed
*
* Store this function in the HCD's struct pci_driver as .resume_early.
*/
int usb_hcd_pci_resume_early(struct pci_dev *dev)
{
pci_restore_state(dev);
return 0;
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_resume_early);

/**
* usb_hcd_pci_resume - power management resume of a PCI-based HCD
* @dev: USB Host Controller being resumed
Expand All @@ -333,6 +320,8 @@ int usb_hcd_pci_resume(struct pci_dev *dev)
}
#endif

pci_restore_state(dev);

hcd = pci_get_drvdata(dev);
if (hcd->state != HC_STATE_SUSPENDED) {
dev_dbg(hcd->self.controller,
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1 change: 0 additions & 1 deletion drivers/usb/core/hcd.h
Original file line number Diff line number Diff line change
Expand Up @@ -257,7 +257,6 @@ extern void usb_hcd_pci_remove(struct pci_dev *dev);

#ifdef CONFIG_PM
extern int usb_hcd_pci_suspend(struct pci_dev *dev, pm_message_t msg);
extern int usb_hcd_pci_resume_early(struct pci_dev *dev);
extern int usb_hcd_pci_resume(struct pci_dev *dev);
#endif /* CONFIG_PM */

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1 change: 0 additions & 1 deletion drivers/usb/host/ehci-pci.c
Original file line number Diff line number Diff line change
Expand Up @@ -432,7 +432,6 @@ static struct pci_driver ehci_pci_driver = {

#ifdef CONFIG_PM
.suspend = usb_hcd_pci_suspend,
.resume_early = usb_hcd_pci_resume_early,
.resume = usb_hcd_pci_resume,
#endif
.shutdown = usb_hcd_pci_shutdown,
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1 change: 0 additions & 1 deletion drivers/usb/host/ohci-pci.c
Original file line number Diff line number Diff line change
Expand Up @@ -487,7 +487,6 @@ static struct pci_driver ohci_pci_driver = {

#ifdef CONFIG_PM
.suspend = usb_hcd_pci_suspend,
.resume_early = usb_hcd_pci_resume_early,
.resume = usb_hcd_pci_resume,
#endif

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1 change: 0 additions & 1 deletion drivers/usb/host/uhci-hcd.c
Original file line number Diff line number Diff line change
Expand Up @@ -942,7 +942,6 @@ static struct pci_driver uhci_pci_driver = {

#ifdef CONFIG_PM
.suspend = usb_hcd_pci_suspend,
.resume_early = usb_hcd_pci_resume_early,
.resume = usb_hcd_pci_resume,
#endif /* PM */
};
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