Since a_alt_hnp_support is obsolete in OTG 2.0, HNP capable host should send this set feature request only if the otg device is connecting to a non-HNP port and it's compliant with OTG 1.x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 <[email protected]> --- drivers/usb/core/hub.c | 45 +++++++++++++++++++++++++++++---------------- 1 file changed, 29 insertions(+), 16 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 917c27c..47dca78 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2254,23 +2254,36 @@ static int usb_enumerate_device_otg(struct usb_device *udev) ? "" : "non-"); /* enable HNP before suspend, it's simpler */ - if (port1 == bus->otg_port) + 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; + 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_info(&udev->dev, + "can't set HNP mode: %d\n", + err); + bus->b_hnp_enable = 0; + } + } else if (desc->bLength == sizeof + (struct usb_otg_descriptor)) { + 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_info(&udev->dev, + "set a_alt_hnp_support failed: %d\n", + err); } } } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
