From: Wang Zhi <zhi.wang@windriver.com>
Date: Wed, 17 Aug 2011 02:39:31 +0000 (+0800)
Subject: USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume().
X-Git-Tag: v3.0.5~220
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=cde5eaf3ce98af402a91fa67ba392f6451f5bc89;p=karo-tx-linux.git

USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume().

commit d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80 upstream.

From EHCI Spec p.28 HC should clear PORT_SUSPEND when SW clears
PORT_RESUME. In Intel Oaktrail platform, MPH (Multi-Port Host
Controller) core clears PORT_SUSPEND directly when SW sets PORT_RESUME
bit. If we rely on PORT_SUSPEND bit to stop USB resume, we will miss
the action of clearing PORT_RESUME. This will cause unexpected long
resume signal on USB bus.

Signed-off-by: Wang Zhi <zhi.wang@windriver.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 88cfb8fadb70..0f3a72480084 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -343,7 +343,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 	u32			temp;
 	u32			power_okay;
 	int			i;
-	u8			resume_needed = 0;
+	unsigned long		resume_needed = 0;
 
 	if (time_before (jiffies, ehci->next_statechange))
 		msleep(5);
@@ -416,7 +416,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 		if (test_bit(i, &ehci->bus_suspended) &&
 				(temp & PORT_SUSPEND)) {
 			temp |= PORT_RESUME;
-			resume_needed = 1;
+			set_bit(i, &resume_needed);
 		}
 		ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
 	}
@@ -431,8 +431,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 	i = HCS_N_PORTS (ehci->hcs_params);
 	while (i--) {
 		temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
-		if (test_bit(i, &ehci->bus_suspended) &&
-				(temp & PORT_SUSPEND)) {
+		if (test_bit(i, &resume_needed)) {
 			temp &= ~(PORT_RWC_BITS | PORT_RESUME);
 			ehci_writel(ehci, temp, &ehci->regs->port_status [i]);
 			ehci_vdbg (ehci, "resumed port %d\n", i + 1);