[PATCH v3] usb/host/ehci-hub: Fix the issue EG20T USB host controller has long resuming time, when pen drive is attached.

[Tomoya MORINAGA <tomoya.rohm@xxxxxxxxx>]

Intel EG20T USB host controller does not send SOF in resuming time after
suspending, if the FLR bit was not cleared. When pen drive is attached,
the controller has a long resuming time to try re-connect it.
This patch clear the FLR bit in suspending time for fixing the issue.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@xxxxxxxxx>
---
v3: Update comments from Alan Stern
	Add comment in the source code.

v2: Update comments from Alan Stern
        Add patch description
        Always clear the STS_FLR flag.
---
 drivers/usb/host/ehci-hub.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index fc9e7cc..278b589 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -318,6 +318,13 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
 	ehci_readl(ehci, &ehci->regs->intr_enable);
 
 	ehci->next_statechange = jiffies + msecs_to_jiffies(10);
+
+	/* Intel EG20T USB host controller does not send SOF
+	 * in resuming time after suspending, if the FLR bit was not cleared.
+	 * Therefore clear the FLR bit in here.
+	 */
+	ehci_writel(ehci, STS_FLR, &ehci->regs->status);
+
 	spin_unlock_irq (&ehci->lock);
 
 	/* ehci_work() may have re-enabled the watchdog timer, which we do not
-- 
1.7.4.4

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