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;