[PATCH] UHCI: remove hc_inaccessible flag

This patch (as706) removes the private hc_inaccessible flag from
uhci-hcd.  It's not needed because it conveys exactly the same
information as the generic HCD_FLAG_HW_ACCESSIBLE bit.

In its place goes a new flag recording whether the controller is dead.
The new code allows a complete device reset to resurrect a dead
controller (although usbcore doesn't yet implement such a facility).

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 29 insertions, 26 deletions

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index dc9ed29c6175..025b969f95e8 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -110,17 +110,23 @@ static void finish_reset(struct uhci_hcd *uhci)
         uhci->is_stopped = UHCI_IS_STOPPED;
         uhci_to_hcd(uhci)->state = HC_STATE_HALT;
         uhci_to_hcd(uhci)->poll_rh = 0;
+
+        uhci->dead = 0;         /* Full reset resurrects the controller */
 }
 
 /*
  * Last rites for a defunct/nonfunctional controller
  * or one we don't want to use any more.
  */
-static void hc_died(struct uhci_hcd *uhci)
+static void uhci_hc_died(struct uhci_hcd *uhci)
 {
+        uhci_get_current_frame_number(uhci);
         uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
         finish_reset(uhci);
-        uhci->hc_inaccessible = 1;
+        uhci->dead = 1;
+
+        /* The current frame may already be partway finished */
+        ++uhci->frame_number;
 }
 
 /*
@@ -234,7 +240,7 @@ __acquires(uhci->lock)
                 spin_unlock_irq(&uhci->lock);
                 msleep(1);
                 spin_lock_irq(&uhci->lock);
-                if (uhci->hc_inaccessible)      /* Died */
+                if (uhci->dead)
                         return;
         }
         if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
@@ -287,7 +293,7 @@ __acquires(uhci->lock)
                 spin_unlock_irq(&uhci->lock);
                 msleep(20);
                 spin_lock_irq(&uhci->lock);
-                if (uhci->hc_inaccessible)      /* Died */
+                if (uhci->dead)
                         return;
 
                 /* End Global Resume and wait for EOP to be sent */
@@ -339,7 +345,7 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
                                                         errbuf, ERRBUF_LEN);
                                         lprintk(errbuf);
                                 }
-                                hc_died(uhci);
+                                uhci_hc_died(uhci);
 
                                 /* Force a callback in case there are
                                  * pending unlinks */
@@ -462,7 +468,7 @@ static void uhci_shutdown(struct pci_dev *pdev)
 {
         struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
 
-        hc_died(hcd_to_uhci(hcd));
+        uhci_hc_died(hcd_to_uhci(hcd));
 }
 
 /*
@@ -664,8 +670,8 @@ static void uhci_stop(struct usb_hcd *hcd)
         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
 
         spin_lock_irq(&uhci->lock);
-        if (!uhci->hc_inaccessible)
-                hc_died(uhci);
+        if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) && !uhci->dead)
+                uhci_hc_died(uhci);
         uhci_scan_schedule(uhci, NULL);
         spin_unlock_irq(&uhci->lock);
 
@@ -681,7 +687,7 @@ static int uhci_rh_suspend(struct usb_hcd *hcd)
         spin_lock_irq(&uhci->lock);
         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
                 rc = -ESHUTDOWN;
-        else if (!uhci->hc_inaccessible)
+        else if (!uhci->dead)
                 suspend_rh(uhci, UHCI_RH_SUSPENDED);
         spin_unlock_irq(&uhci->lock);
         return rc;
@@ -696,7 +702,7 @@ static int uhci_rh_resume(struct usb_hcd *hcd)
         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
                 dev_warn(&hcd->self.root_hub->dev, "HC isn't running!\n");
                 rc = -ESHUTDOWN;
-        } else if (!uhci->hc_inaccessible)
+        } else if (!uhci->dead)
                 wakeup_rh(uhci);
         spin_unlock_irq(&uhci->lock);
         return rc;
@@ -710,8 +716,8 @@ static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
         dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
 
         spin_lock_irq(&uhci->lock);
-        if (uhci->hc_inaccessible)      /* Dead or already suspended */
-                goto done;
+        if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
+                goto done_okay;         /* Already suspended or dead */
 
         if (uhci->rh_state > UHCI_RH_SUSPENDED) {
                 dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
@@ -724,12 +730,12 @@ static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
          */
         pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
         mb();
-        clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-        uhci->hc_inaccessible = 1;
         hcd->poll_rh = 0;
 
         /* FIXME: Enable non-PME# remote wakeup? */
 
+done_okay:
+        clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 done:
         spin_unlock_irq(&uhci->lock);
         return rc;
@@ -742,25 +748,22 @@ static int uhci_resume(struct usb_hcd *hcd)
         dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
 
         /* Since we aren't in D3 any more, it's safe to set this flag
-         * even if the controller was dead.  It might not even be dead
-         * any more, if the firmware or quirks code has reset it.
+         * even if the controller was dead.
          */
         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
         mb();
 
-        if (uhci->rh_state == UHCI_RH_RESET)    /* Dead */
-                return 0;
-
         spin_lock_irq(&uhci->lock);
 
         /* FIXME: Disable non-PME# remote wakeup? */
 
-        uhci->hc_inaccessible = 0;
-
-        /* The BIOS may have changed the controller settings during a
-         * system wakeup.  Check it and reconfigure to avoid problems.
+        /* The firmware or a boot kernel may have changed the controller
+         * settings during a system wakeup.  Check it and reconfigure
+         * to avoid problems.
          */
         check_and_reset_hc(uhci);
+
+        /* If the controller was dead before, it's back alive now */
         configure_hc(uhci);
 
         if (uhci->rh_state == UHCI_RH_RESET) {
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 469b4268b850..619d704f4e8f 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -395,7 +395,7 @@ struct uhci_hcd {
 
         unsigned int scan_in_progress:1;        /* Schedule scan is running */
         unsigned int need_rescan:1;             /* Redo the schedule scan */
-        unsigned int hc_inaccessible:1;         /* HC is suspended or dead */
+        unsigned int dead:1;                    /* Controller has died */
         unsigned int working_RD:1;              /* Suspended root hub doesn't
                                                    need to be polled */
         unsigned int is_initialized:1;          /* Data structure is usable */
diff --git a/drivers/usb/host/uhci-hub.c b/drivers/usb/host/uhci-hub.c
index f53c116e0dfd..c545ef92fe29 100644
--- a/drivers/usb/host/uhci-hub.c
+++ b/drivers/usb/host/uhci-hub.c
@@ -171,7 +171,7 @@ static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
         spin_lock_irqsave(&uhci->lock, flags);
 
         uhci_scan_schedule(uhci, NULL);
-        if (uhci->hc_inaccessible)
+        if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
                 goto done;
         uhci_check_ports(uhci);
 
@@ -227,7 +227,7 @@ static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
         u16 wPortChange, wPortStatus;
         unsigned long flags;
 
-        if (uhci->hc_inaccessible)
+        if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
                 return -ETIMEDOUT;
 
         spin_lock_irqsave(&uhci->lock, flags);