From 094e3cd2841f9d603bbd5db176b675c6253e9153 Mon Sep 17 00:00:00 2001
From: David Brownell <david-b@pacbell.net>
Date: Sat, 2 Feb 2008 02:42:52 -0800
Subject: [PATCH] --- yaml --- r: 93280 b: refs/heads/master c:
 e01e7fe3886715f083313da409c5850472455d06 h: refs/heads/master v: v3

---
 [refs]                            |  2 +-
 trunk/drivers/usb/host/ohci-hub.c | 24 +++++++++++++++++++++---
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 0a52faa1f57a..0f3c41da2c01 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9776afc8b3dc487557f3f576002520f59be334e6
+refs/heads/master: e01e7fe3886715f083313da409c5850472455d06
diff --git a/trunk/drivers/usb/host/ohci-hub.c b/trunk/drivers/usb/host/ohci-hub.c
index 48e4b11f4d3e..c638e6b33c43 100644
--- a/trunk/drivers/usb/host/ohci-hub.c
+++ b/trunk/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;
 }