USB: EHCI: EHCI 1.1 addendum: Basic LPM feature support

With this patch, the LPM capable EHCI host controller can put device
into L1 sleep state which is a mode that can enter/exit quickly, and
reduce power consumption.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index e7d3d8def282..8a28dae8a375 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -790,6 +790,11 @@ static int ehci_hub_control (
                                           status_reg);
                         break;
                 case USB_PORT_FEAT_C_CONNECTION:
+                        if (ehci->has_lpm) {
+                                /* clear PORTSC bits on disconnect */
+                                temp &= ~PORT_LPM;
+                                temp &= ~PORT_DEV_ADDR;
+                        }
                         ehci_writel(ehci, (temp & ~PORT_RWC_BITS) | PORT_CSC,
                                         status_reg);
                         break;