PM: USB HCDs use PM_EVENT_PRETHAW

This teaches several USB host controller drivers to treat PRETHAW as a chip
reset since the controller, and all devices connected to it, are no longer in
states compatible with how the snapshotted suspend() left them.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 23 insertions, 3 deletions

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 5078fb3375e3..fa36391fedd3 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -281,7 +281,7 @@ int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
                         (void) usb_hcd_pci_resume (dev);
                 }
 
-        } else {
+        } else if (hcd->state != HC_STATE_HALT) {
                 dev_dbg (hcd->self.controller, "hcd state %d; not suspended\n",
                         hcd->state);
                 WARN_ON(1);
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index cadffacd945b..6967ab71e282 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -238,6 +238,12 @@ static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
         writel (0, &ehci->regs->intr_enable);
         (void)readl(&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);
diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index b268537e389e..37e122812b67 100644
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -135,6 +135,11 @@ static int ohci_pci_suspend (struct usb_hcd *hcd, pm_message_t message)
         }
         ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
         (void)ohci_readl(ohci, &ohci->regs->intrdisable);
+
+        /* make sure snapshot being resumed re-enumerates everything */
+        if (message.event == PM_EVENT_PRETHAW)
+                ohci_usb_reset(ohci);
+
         clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
  bail:
         spin_unlock_irqrestore (&ohci->lock, flags);
diff --git a/drivers/usb/host/sl811-hcd.c b/drivers/usb/host/sl811-hcd.c
index fa34092bbcde..9de115d9db27 100644
--- a/drivers/usb/host/sl811-hcd.c
+++ b/drivers/usb/host/sl811-hcd.c
@@ -1783,10 +1783,15 @@ sl811h_suspend(struct platform_device *dev, pm_message_t state)
         struct sl811    *sl811 = hcd_to_sl811(hcd);
         int             retval = 0;
 
-        if (state.event == PM_EVENT_FREEZE)
+        switch (state.event) {
+        case PM_EVENT_FREEZE:
                 retval = sl811h_bus_suspend(hcd);
-        else if (state.event == PM_EVENT_SUSPEND)
+                break;
+        case PM_EVENT_SUSPEND:
+        case PM_EVENT_PRETHAW:          /* explicitly discard hw state */
                 port_power(sl811, 0);
+                break;
+        }
         if (retval == 0)
                 dev->dev.power.power_state = state;
         return retval;
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 4151f618602d..b7402ceb3e93 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -734,6 +734,10 @@ static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
 
         /* FIXME: Enable non-PME# remote wakeup? */
 
+        /* make sure snapshot being resumed re-enumerates everything */
+        if (message.event == PM_EVENT_PRETHAW)
+                uhci_hc_died(uhci);
+
 done_okay:
         clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 done: