usb: xhci: check usb2 port capabilities before adding hw link PM support

Hardware link powermanagement in usb2 is a per-port capability.
Previously support for hw lpm was enabled for all ports if any usb2 port supported it.

Now instead cache the capability values and check them for each port individually

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 2cfc465..832f05e 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1852,6 +1852,7 @@
 	kfree(xhci->usb3_ports);
 	kfree(xhci->port_array);
 	kfree(xhci->rh_bw);
+	kfree(xhci->ext_caps);
 
 	xhci->page_size = 0;
 	xhci->page_shift = 0;
@@ -2039,7 +2040,7 @@
 }
 
 static void xhci_add_in_port(struct xhci_hcd *xhci, unsigned int num_ports,
-		__le32 __iomem *addr, u8 major_revision)
+		__le32 __iomem *addr, u8 major_revision, int max_caps)
 {
 	u32 temp, port_offset, port_count;
 	int i;
@@ -2064,6 +2065,10 @@
 		/* WTF? "Valid values are ‘1’ to MaxPorts" */
 		return;
 
+	/* cache usb2 port capabilities */
+	if (major_revision < 0x03 && xhci->num_ext_caps < max_caps)
+		xhci->ext_caps[xhci->num_ext_caps++] = temp;
+
 	/* Check the host's USB2 LPM capability */
 	if ((xhci->hci_version == 0x96) && (major_revision != 0x03) &&
 			(temp & XHCI_L1C)) {
@@ -2121,10 +2126,11 @@
  */
 static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
 {
-	__le32 __iomem *addr;
-	u32 offset;
+	__le32 __iomem *addr, *tmp_addr;
+	u32 offset, tmp_offset;
 	unsigned int num_ports;
 	int i, j, port_index;
+	int cap_count = 0;
 
 	addr = &xhci->cap_regs->hcc_params;
 	offset = XHCI_HCC_EXT_CAPS(xhci_readl(xhci, addr));
@@ -2157,13 +2163,32 @@
 	 * See section 5.3.6 for offset calculation.
 	 */
 	addr = &xhci->cap_regs->hc_capbase + offset;
+
+	tmp_addr = addr;
+	tmp_offset = offset;
+
+	/* count extended protocol capability entries for later caching */
+	do {
+		u32 cap_id;
+		cap_id = xhci_readl(xhci, tmp_addr);
+		if (XHCI_EXT_CAPS_ID(cap_id) == XHCI_EXT_CAPS_PROTOCOL)
+			cap_count++;
+		tmp_offset = XHCI_EXT_CAPS_NEXT(cap_id);
+		tmp_addr += tmp_offset;
+	} while (tmp_offset);
+
+	xhci->ext_caps = kzalloc(sizeof(*xhci->ext_caps) * cap_count, flags);
+	if (!xhci->ext_caps)
+		return -ENOMEM;
+
 	while (1) {
 		u32 cap_id;
 
 		cap_id = xhci_readl(xhci, addr);
 		if (XHCI_EXT_CAPS_ID(cap_id) == XHCI_EXT_CAPS_PROTOCOL)
 			xhci_add_in_port(xhci, num_ports, addr,
-					(u8) XHCI_EXT_PORT_MAJOR(cap_id));
+					(u8) XHCI_EXT_PORT_MAJOR(cap_id),
+					cap_count);
 		offset = XHCI_EXT_CAPS_NEXT(cap_id);
 		if (!offset || (xhci->num_usb2_ports + xhci->num_usb3_ports)
 				== num_ports)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 4a05555b..df5e881 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4033,15 +4033,40 @@
 	return 0;
 }
 
+/* check if a usb2 port supports a given extened capability protocol
+ * only USB2 ports extended protocol capability values are cached.
+ * Return 1 if capability is supported
+ */
+static int xhci_check_usb2_port_capability(struct xhci_hcd *xhci, int port,
+					   unsigned capability)
+{
+	u32 port_offset, port_count;
+	int i;
+
+	for (i = 0; i < xhci->num_ext_caps; i++) {
+		if (xhci->ext_caps[i] & capability) {
+			/* port offsets starts at 1 */
+			port_offset = XHCI_EXT_PORT_OFF(xhci->ext_caps[i]) - 1;
+			port_count = XHCI_EXT_PORT_COUNT(xhci->ext_caps[i]);
+			if (port >= port_offset &&
+			    port < port_offset + port_count)
+				return 1;
+		}
+	}
+	return 0;
+}
+
 int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
 {
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 	int		ret;
+	int		portnum = udev->portnum - 1;
 
 	ret = xhci_usb2_software_lpm_test(hcd, udev);
 	if (!ret) {
 		xhci_dbg(xhci, "software LPM test succeed\n");
-		if (xhci->hw_lpm_support == 1) {
+		if (xhci->hw_lpm_support == 1 &&
+		    xhci_check_usb2_port_capability(xhci, portnum, XHCI_HLC)) {
 			udev->usb2_hw_lpm_capable = 1;
 			ret = xhci_set_usb2_hardware_lpm(hcd, udev, 1);
 			if (!ret)
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index d62ebca..66b048a 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1532,6 +1532,9 @@
 	unsigned		sw_lpm_support:1;
 	/* support xHCI 1.0 spec USB2 hardware LPM */
 	unsigned		hw_lpm_support:1;
+	/* cached usb2 extened protocol capabilites */
+	u32                     *ext_caps;
+	unsigned int            num_ext_caps;
 	/* Compliance Mode Recovery Data */
 	struct timer_list	comp_mode_recovery_timer;
 	u32			port_status_u0;