USB: new flag for resume-from-hibernation

This patch (as1237) changes the way the PCI host controller drivers
avoid retaining bogus hardware states during resume-from-hibernation.
Previously we had reset the hardware as part of preparing to reinstate
the memory image.  But we can do better now with the new PM framework,
since we know exactly which resume operations are from hibernation.

The pci_resume method is changed to accept a flag indicating whether
the system is resuming from hibernation.  When this flag is set, the
drivers will reset the hardware to get rid of any existing state.

Similarly, the pci_suspend method is changed to remove the
pm_message_t argument.  It's no longer needed, since no special action
has to be taken when preparing to reinstate the memory image.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 11 deletions

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 8172383e8908..e74948898f76 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -268,7 +268,7 @@ done:
  * Also they depend on separate root hub suspend/resume.
  */
 
-static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
+static int ehci_pci_suspend(struct usb_hcd *hcd)
 {
         struct ehci_hcd         *ehci = hcd_to_ehci(hcd);
         unsigned long           flags;
@@ -293,12 +293,6 @@ static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
         ehci_writel(ehci, 0, &ehci->regs->intr_enable);
         (void)ehci_readl(ehci, &ehci->regs->intr_enable);
 
-        /* make sure snapshot being resumed re-enumerates everything */
-        if (message.event == PM_EVENT_PRETHAW) {
-                ehci_halt(ehci);
-                ehci_reset(ehci);
-        }
-
         clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
  bail:
         spin_unlock_irqrestore (&ehci->lock, flags);
@@ -309,7 +303,7 @@ static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
         return rc;
 }
 
-static int ehci_pci_resume(struct usb_hcd *hcd)
+static int ehci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 {
         struct ehci_hcd         *ehci = hcd_to_ehci(hcd);
         struct pci_dev          *pdev = to_pci_dev(hcd->self.controller);
@@ -322,10 +316,12 @@ static int ehci_pci_resume(struct usb_hcd *hcd)
         /* Mark hardware accessible again as we are out of D3 state by now */
         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 
-        /* If CF is still set, we maintained PCI Vaux power.
+        /* If CF is still set and we aren't resuming from hibernation
+         * then we maintained PCI Vaux power.
          * Just undo the effect of ehci_pci_suspend().
          */
-        if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF) {
+        if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF &&
+                                !hibernated) {
                 int     mask = INTR_MASK;
 
                 if (!hcd->self.root_hub->do_remote_wakeup)
@@ -335,7 +331,6 @@ static int ehci_pci_resume(struct usb_hcd *hcd)
                 return 0;
         }
 
-        ehci_dbg(ehci, "lost power, restarting\n");
         usb_root_hub_lost_power(hcd->self.root_hub);
 
         /* Else reset, to cope with power loss or flush-to-storage