usb: otg: don't set a_alt_hnp_support feature for OTG 2.0 device

Since a_alt_hnp_support is obsolete in OTG 2.0, HNP capable host should
send this set feature request only if the otg device is connecting to a
non-HNP port and it's compliant with OTG 1.x revision. This is done by
checking its otg descriptor length, OTG 2.0 uses usb_otg20_descriptor
which has different length than OTG 1.x using usb_otg_descriptor.

Signed-off-by: Li Jun <jun.li@freescale.com>
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 52427267e2a8eacf0ca2452fa59283c2ce492a77..bdeadc112d29f9b4545bf3ab82645b52982f5cfd 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2239,39 +2239,49 @@ static int usb_enumerate_device_otg(struct usb_device *udev)
                        && udev->parent == udev->bus->root_hub) {
                struct usb_otg_descriptor       *desc = NULL;
                struct usb_bus                  *bus = udev->bus;
+               unsigned                        port1 = udev->portnum;
 
                /* descriptor may appear anywhere in config */
-               if (__usb_get_extra_descriptor(udev->rawdescriptors[0],
-                                       le16_to_cpu(udev->config[0].desc.wTotalLength),
-                                       USB_DT_OTG, (void **) &desc) == 0) {
-                       if (desc->bmAttributes & USB_OTG_HNP) {
-                               unsigned                port1 = udev->portnum;
+               err = __usb_get_extra_descriptor(udev->rawdescriptors[0],
+                               le16_to_cpu(udev->config[0].desc.wTotalLength),
+                               USB_DT_OTG, (void **) &desc);
+               if (err || !(desc->bmAttributes & USB_OTG_HNP))
+                       return 0;
 
-                               dev_info(&udev->dev,
-                                       "Dual-Role OTG device on %sHNP port\n",
-                                       (port1 == bus->otg_port)
-                                               ? "" : "non-");
-
-                               /* enable HNP before suspend, it's simpler */
-                               if (port1 == bus->otg_port)
-                                       bus->b_hnp_enable = 1;
-                               err = usb_control_msg(udev,
-                                       usb_sndctrlpipe(udev, 0),
-                                       USB_REQ_SET_FEATURE, 0,
-                                       bus->b_hnp_enable
-                                               ? USB_DEVICE_B_HNP_ENABLE
-                                               : USB_DEVICE_A_ALT_HNP_SUPPORT,
-                                       0, NULL, 0, USB_CTRL_SET_TIMEOUT);
-                               if (err < 0) {
-                                       /* OTG MESSAGE: report errors here,
-                                        * customize to match your product.
-                                        */
-                                       dev_info(&udev->dev,
-                                               "can't set HNP mode: %d\n",
-                                               err);
-                                       bus->b_hnp_enable = 0;
-                               }
+               dev_info(&udev->dev, "Dual-Role OTG device on %sHNP port\n",
+                                       (port1 == bus->otg_port) ? "" : "non-");
+
+               /* enable HNP before suspend, it's simpler */
+               if (port1 == bus->otg_port) {
+                       bus->b_hnp_enable = 1;
+                       err = usb_control_msg(udev,
+                               usb_sndctrlpipe(udev, 0),
+                               USB_REQ_SET_FEATURE, 0,
+                               USB_DEVICE_B_HNP_ENABLE,
+                               0, NULL, 0,
+                               USB_CTRL_SET_TIMEOUT);
+                       if (err < 0) {
+                               /*
+                                * OTG MESSAGE: report errors here,
+                                * customize to match your product.
+                                */
+                               dev_err(&udev->dev, "can't set HNP mode: %d\n",
+                                                                       err);
+                               bus->b_hnp_enable = 0;
                        }
+               } else if (desc->bLength == sizeof
+                               (struct usb_otg_descriptor)) {
+                       /* Set a_alt_hnp_support for legacy otg device */
+                       err = usb_control_msg(udev,
+                               usb_sndctrlpipe(udev, 0),
+                               USB_REQ_SET_FEATURE, 0,
+                               USB_DEVICE_A_ALT_HNP_SUPPORT,
+                               0, NULL, 0,
+                               USB_CTRL_SET_TIMEOUT);
+                       if (err < 0)
+                               dev_err(&udev->dev,
+                                       "set a_alt_hnp_support failed: %d\n",
+                                       err);
                }
        }
 #endif