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

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>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index e051b30c1847..4c32cb19b405 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);