[PATCH] USB: EHCI updates

This fixes some bugs in EHCI suspend/resume that joined us over the past
few releases (as usbcore, PCI, pmcore, and other components evolved):

  - Removes suspend and resume recursion from the EHCI driver, getting
    rid of the USB_SUSPEND special casing.

  - Updates the wakeup mechanism to work again; there's a newish usbcore
    call it needs to use.

  - Provide simpler tests for "do we need to restart from scratch", to
    address another case where PCI Vaux was lost.  (In this case it was
    restoring a swsusp snapshot, but there could be others.)

Un-exports a symbol that was temporarily exported.

A notable change from previous version is that this doesn't move
the spinlock init, so there's still a resume/reinit path bug.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 46 insertions, 42 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 840727948d84..f78bd124d290 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1669,7 +1669,6 @@ int usb_suspend_device(struct usb_device *udev)
         return 0;
 #endif
 }
-EXPORT_SYMBOL_GPL(usb_suspend_device);
 
 /*
  * If the USB "suspend" state is in use (rather than "global suspend"),
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index af3c05eb86fc..f15144e96e14 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -636,9 +636,8 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd, struct pt_regs *regs)
                          * stop that signaling.
                          */
                         ehci->reset_done [i] = jiffies + msecs_to_jiffies (20);
-                        mod_timer (&hcd->rh_timer,
-                                        ehci->reset_done [i] + 1);
                         ehci_dbg (ehci, "port %d remote wakeup\n", i + 1);
+                        usb_hcd_resume_root_hub(hcd);
                 }
         }
 
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 88cb4ada686e..82caf336e9b6 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -94,6 +94,13 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
                 msleep(5);
         spin_lock_irq (&ehci->lock);
 
+        /* Ideally and we've got a real resume here, and no port's power
+         * was lost.  (For PCI, that means Vaux was maintained.)  But we
+         * could instead be restoring a swsusp snapshot -- so that BIOS was
+         * the last user of the controller, not reset/pm hardware keeping
+         * state we gave to it.
+         */
+
         /* re-init operational registers in case we lost power */
         if (readl (&ehci->regs->intr_enable) == 0) {
                 /* at least some APM implementations will try to deliver
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index dfd9bd0b1828..0f2be91e5e0e 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -235,10 +235,11 @@ static void ehci_pci_stop (struct usb_hcd *hcd)
 
 /* suspend/resume, section 4.3 */
 
-/* These routines rely on the bus (pci, platform, etc)
+/* These routines rely on the PCI bus glue
  * to handle powerdown and wakeup, and currently also on
  * transceivers that don't need any software attention to set up
  * the right sort of wakeup.
+ * Also they depend on separate root hub suspend/resume.
  */
 
 static int ehci_pci_suspend (struct usb_hcd *hcd, pm_message_t message)
@@ -246,17 +247,9 @@ static int ehci_pci_suspend (struct usb_hcd *hcd, pm_message_t message)
         struct ehci_hcd         *ehci = hcd_to_ehci (hcd);
 
         if (time_before (jiffies, ehci->next_statechange))
-                msleep (100);
-
-#ifdef  CONFIG_USB_SUSPEND
-        (void) usb_suspend_device (hcd->self.root_hub);
-#else
-        usb_lock_device (hcd->self.root_hub);
-        (void) ehci_bus_suspend (hcd);
-        usb_unlock_device (hcd->self.root_hub);
-#endif
+                msleep (10);
 
-        // save (PCI) FLADJ in case of Vaux power loss
+        // could save FLADJ in case of Vaux power loss
         // ... we'd only use it to handle clock skew
 
         return 0;
@@ -269,13 +262,18 @@ static int ehci_pci_resume (struct usb_hcd *hcd)
         struct usb_device       *root = hcd->self.root_hub;
         int                     retval = -EINVAL;
 
-        // maybe restore (PCI) FLADJ
+        // maybe restore FLADJ
 
         if (time_before (jiffies, ehci->next_statechange))
                 msleep (100);
 
+        /* If CF is clear, we lost PCI Vaux power and need to restart.  */
+        if (readl (&ehci->regs->configured_flag) != cpu_to_le32(FLAG_CF))
+                goto restart;
+
         /* If any port is suspended (or owned by the companion),
          * we know we can/must resume the HC (and mustn't reset it).
+         * We just defer that to the root hub code.
          */
         for (port = HCS_N_PORTS (ehci->hcs_params); port > 0; ) {
                 u32     status;
@@ -283,42 +281,43 @@ static int ehci_pci_resume (struct usb_hcd *hcd)
                 status = readl (&ehci->regs->port_status [port]);
                 if (!(status & PORT_POWER))
                         continue;
-                if (status & (PORT_SUSPEND | PORT_OWNER)) {
-                        down (&hcd->self.root_hub->serialize);
-                        retval = ehci_bus_resume (hcd);
-                        up (&hcd->self.root_hub->serialize);
-                        break;
+                if (status & (PORT_SUSPEND | PORT_RESUME | PORT_OWNER)) {
+                        usb_hcd_resume_root_hub(hcd);
+                        return 0;
                 }
+        }
+
+restart:
+        ehci_dbg(ehci, "lost power, restarting\n");
+        for (port = HCS_N_PORTS (ehci->hcs_params); port > 0; ) {
+                port--;
                 if (!root->children [port])
                         continue;
-                dbg_port (ehci, __FUNCTION__, port + 1, status);
                 usb_set_device_state (root->children[port],
                                         USB_STATE_NOTATTACHED);
         }
 
         /* Else reset, to cope with power loss or flush-to-storage
-         * style "resume" having activated BIOS during reboot.
+         * style "resume" having let BIOS kick in during reboot.
          */
-        if (port == 0) {
-                (void) ehci_halt (ehci);
-                (void) ehci_reset (ehci);
-                (void) ehci_pci_reset (hcd);
-
-                /* emptying the schedule aborts any urbs */
-                spin_lock_irq (&ehci->lock);
-                if (ehci->reclaim)
-                        ehci->reclaim_ready = 1;
-                ehci_work (ehci, NULL);
-                spin_unlock_irq (&ehci->lock);
-
-                /* restart; khubd will disconnect devices */
-                retval = ehci_run (hcd);
-
-                /* here we "know" root ports should always stay powered;
-                 * but some controllers may lose all power.
-                 */
-                ehci_port_power (ehci, 1);
-        }
+        (void) ehci_halt (ehci);
+        (void) ehci_reset (ehci);
+        (void) ehci_pci_reset (hcd);
+
+        /* emptying the schedule aborts any urbs */
+        spin_lock_irq (&ehci->lock);
+        if (ehci->reclaim)
+                ehci->reclaim_ready = 1;
+        ehci_work (ehci, NULL);
+        spin_unlock_irq (&ehci->lock);
+
+        /* restart; khubd will disconnect devices */
+        retval = ehci_run (hcd);
+
+        /* here we "know" root ports should always stay powered;
+         * but some controllers may lose all power.
+         */
+        ehci_port_power (ehci, 1);
 
         return retval;
 }