1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 74bfc868b7ad..d5eb357aa5c4 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -493,11 +493,48 @@ static void xhci_hub_report_link_state(u32 *status, u32 status_reg)
                  * when this bit is set.
                  */
                 pls |= USB_PORT_STAT_CONNECTION;
+        } else {
+                /*
+                 * If CAS bit isn't set but the Port is already at
+                 * Compliance Mode, fake a connection so the USB core
+                 * notices the Compliance state and resets the port.
+                 * This resolves an issue generated by the SN65LVPE502CP
+                 * in which sometimes the port enters compliance mode
+                 * caused by a delay on the host-device negotiation.
+                 */
+                if (pls == USB_SS_PORT_LS_COMP_MOD)
+                        pls |= USB_PORT_STAT_CONNECTION;
         }
+
         /* update status field */
         *status |= pls;
 }
 
+/*
+ * Function for Compliance Mode Quirk.
+ *
+ * This Function verifies if all xhc USB3 ports have entered U0, if so,
+ * the compliance mode timer is deleted. A port won't enter
+ * compliance mode if it has previously entered U0.
+ */
+void xhci_del_comp_mod_timer(struct xhci_hcd *xhci, u32 status, u16 wIndex)
+{
+        u32 all_ports_seen_u0 = ((1 << xhci->num_usb3_ports)-1);
+        bool port_in_u0 = ((status & PORT_PLS_MASK) == XDEV_U0);
+
+        if (!(xhci->quirks & XHCI_COMP_MODE_QUIRK))
+                return;
+
+        if ((xhci->port_status_u0 != all_ports_seen_u0) && port_in_u0) {
+                xhci->port_status_u0 |= 1 << wIndex;
+                if (xhci->port_status_u0 == all_ports_seen_u0) {
+                        del_timer_sync(&xhci->comp_mode_recovery_timer);
+                        xhci_dbg(xhci, "All USB3 ports have entered U0 already!\n");
+                        xhci_dbg(xhci, "Compliance Mode Recovery Timer Deleted.\n");
+                }
+        }
+}
+
 int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                 u16 wIndex, char *buf, u16 wLength)
 {
@@ -651,6 +688,11 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                 /* Update Port Link State for super speed ports*/
                 if (hcd->speed == HCD_USB3) {
                         xhci_hub_report_link_state(&status, temp);
+                        /*
+                         * Verify if all USB3 Ports Have entered U0 already.
+                         * Delete Compliance Mode Timer if so.
+                         */
+                        xhci_del_comp_mod_timer(xhci, temp, wIndex);
                 }
                 if (bus_state->port_c_suspend & (1 << wIndex))
                         status |= 1 << USB_PORT_FEAT_C_SUSPEND;