USB: OHCI: fix endless polling behavior

[linux-2.6-omap-h63xx.git] / drivers / usb / host / ohci-hub.c

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index a150e85c901ac5321e282a9d19eefaca3e37837d..32bbce9718f0626b98cc37e09b14faa51a5cc16f 100644 (file)
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -359,17 +359,15 @@ static void ohci_finish_controller_resume(struct usb_hcd *hcd)
 
 /* Carry out polling-, autostop-, and autoresume-related state changes */
 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
-               int any_connected)
+               int any_connected, int rhsc_status)
 {
        int     poll_rh = 1;
-       int     rhsc_status, rhsc_enable;
+       int     rhsc_enable;
 
        /* Some broken controllers never turn off RHCS in the interrupt
         * status register.  For their sake we won't re-enable RHSC
         * interrupts if the interrupt bit is already active.
         */
-       rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
-                       OHCI_INTR_RHSC;
        rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
                        OHCI_INTR_RHSC;
 
@@ -421,14 +419,23 @@ static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                                ohci_rh_resume(ohci);
                        else
                                usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
+
+               /* If remote wakeup is disabled, stop polling */
+               } else if (!ohci->autostop &&
+                               !ohci_to_hcd(ohci)->self.root_hub->
+                                       do_remote_wakeup) {
+                       poll_rh = 0;
+
                } else {
-                       if (!rhsc_enable && !rhsc_status && (ohci->autostop ||
-                                       ohci_to_hcd(ohci)->self.root_hub->
-                                               do_remote_wakeup)) {
+                       /* If no status changes are pending,
+                        * enable RHSC interrupts
+                        */
+                       if (!rhsc_enable && !rhsc_status) {
                                rhsc_enable = OHCI_INTR_RHSC;
                                ohci_writel(ohci, rhsc_enable,
                                                &ohci->regs->intrenable);
                        }
+                       /* Keep polling until RHSC is enabled */
                        if (rhsc_enable)
                                poll_rh = 0;
                }
@@ -448,22 +455,22 @@ static inline int ohci_rh_resume(struct ohci_hcd *ohci)
  * autostop isn't used when CONFIG_PM is turned off.
  */
 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
-               int any_connected)
+               int any_connected, int rhsc_status)
 {
-       int     rhsc_status;
-
        /* If RHSC is enabled, don't poll */
        if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
                return 0;
 
-       /* If no status changes are pending, enable RHSC interrupts */
-       rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
-                       OHCI_INTR_RHSC;
-       if (!changed && !rhsc_status) {
-               ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
-               return 0;
-       }
-       return 1;
+       /* If status changes are pending, continue polling.
+        * Conversely, if no status changes are pending but the RHSC
+        * status bit was set, then RHSC may be broken so continue polling.
+        */
+       if (changed || rhsc_status)
+               return 1;
+
+       /* It's safe to re-enable RHSC interrupts */
+       ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
+       return 0;
 }
 
 #endif /* CONFIG_PM */
@@ -478,6 +485,7 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        int             i, changed = 0, length = 1;
        int             any_connected = 0;
+       int             rhsc_status;
        unsigned long   flags;
 
        spin_lock_irqsave (&ohci->lock, flags);
@@ -503,6 +511,11 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
                length++;
        }
 
+       /* Clear the RHSC status flag before reading the port statuses */
+       ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
+       rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
+                       OHCI_INTR_RHSC;
+
        /* look at each port */
        for (i = 0; i < ohci->num_ports; i++) {
                u32     status = roothub_portstatus (ohci, i);
@@ -521,7 +534,7 @@ ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
        }
 
        hcd->poll_rh = ohci_root_hub_state_changes(ohci, changed,
-                       any_connected);
+                       any_connected, rhsc_status);
 
 done:
        spin_unlock_irqrestore (&ohci->lock, flags);