1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index bc6ec0cb3c61..9c7ddf0f3a43 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1959,6 +1959,23 @@ static void xhci_add_in_port(struct xhci_hcd *xhci, unsigned int num_ports,
         if (port_offset == 0 || (port_offset + port_count - 1) > num_ports)
                 /* WTF? "Valid values are ‘1’ to MaxPorts" */
                 return;
+
+        /* Check the host's USB2 LPM capability */
+        if ((xhci->hci_version == 0x96) && (major_revision != 0x03) &&
+                        (temp & XHCI_L1C)) {
+                xhci_dbg(xhci, "xHCI 0.96: support USB2 software lpm\n");
+                xhci->sw_lpm_support = 1;
+        }
+
+        if ((xhci->hci_version >= 0x100) && (major_revision != 0x03)) {
+                xhci_dbg(xhci, "xHCI 1.0: support USB2 software lpm\n");
+                xhci->sw_lpm_support = 1;
+                if (temp & XHCI_HLC) {
+                        xhci_dbg(xhci, "xHCI 1.0: support USB2 hardware lpm\n");
+                        xhci->hw_lpm_support = 1;
+                }
+        }
+
         port_offset--;
         for (i = port_offset; i < (port_offset + port_count); i++) {
                 /* Duplicate entry.  Ignore the port if the revisions differ. */