1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 40e0a0c221b8..79ccfe5f8ad0 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -116,6 +116,7 @@ int xhci_reset(struct xhci_hcd *xhci)
 {
         u32 command;
         u32 state;
+        int ret;
 
         state = xhci_readl(xhci, &xhci->op_regs->status);
         if ((state & STS_HALT) == 0) {
@@ -130,7 +131,17 @@ int xhci_reset(struct xhci_hcd *xhci)
         /* XXX: Why does EHCI set this here?  Shouldn't other code do this? */
         xhci_to_hcd(xhci)->state = HC_STATE_HALT;
 
-        return handshake(xhci, &xhci->op_regs->command, CMD_RESET, 0, 250 * 1000);
+        ret = handshake(xhci, &xhci->op_regs->command,
+                        CMD_RESET, 0, 250 * 1000);
+        if (ret)
+                return ret;
+
+        xhci_dbg(xhci, "Wait for controller to be ready for doorbell rings\n");
+        /*
+         * xHCI cannot write to any doorbells or operational registers other
+         * than status until the "Controller Not Ready" flag is cleared.
+         */
+        return handshake(xhci, &xhci->op_regs->status, STS_CNR, 0, 250 * 1000);
 }