1 files changed, 21 insertions, 3 deletions

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index 48e4b11f4d3e..c638e6b33c43 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -564,14 +564,18 @@ static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
         u32     temp;
         u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
         u16     reset_done = now + PORT_RESET_MSEC;
+        int     limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
 
         /* build a "continuous enough" reset signal, with up to
          * 3msec gap between pulses.  scheduler HZ==100 must work;
          * this might need to be deadline-scheduled.
          */
         do {
+                int limit_2;
+
                 /* spin until any current reset finishes */
-                for (;;) {
+                limit_2 = PORT_RESET_HW_MSEC * 2;
+                while (--limit_2 >= 0) {
                         temp = ohci_readl (ohci, portstat);
                         /* handle e.g. CardBus eject */
                         if (temp == ~(u32)0)
@@ -581,6 +585,17 @@ static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
                         udelay (500);
                 }
 
+                /* timeout (a hardware error) has been observed when
+                 * EHCI sets CF while this driver is resetting a port;
+                 * presumably other disconnect paths might do it too.
+                 */
+                if (limit_2 < 0) {
+                        ohci_dbg(ohci,
+                                "port[%d] reset timeout, stat %08x\n",
+                                port, temp);
+                        break;
+                }
+
                 if (!(temp & RH_PS_CCS))
                         break;
                 if (temp & RH_PS_PRSC)
@@ -590,8 +605,11 @@ static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
                 ohci_writel (ohci, RH_PS_PRS, portstat);
                 msleep(PORT_RESET_HW_MSEC);
                 now = ohci_readl(ohci, &ohci->regs->fmnumber);
-        } while (tick_before(now, reset_done));
-        /* caller synchronizes using PRSC */
+        } while (tick_before(now, reset_done) && --limit_1 >= 0);
+
+        /* caller synchronizes using PRSC ... and handles PRS
+         * still being set when this returns.
+         */
 
         return 0;
 }