Since a_alt_hnp_support is obsolete in OTG 2.0, HNP capable host should send this set feature request only if the otg device is connecting to a non-HNP port and it's compliant with OTG 1.x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@xxxxxxxxxxxxx> --- Changes for v2: - Change dev_info to be dev_err if set otg features failed. - Coding style update for line charactors less than 80. drivers/usb/core/hub.c | 68 +++++++++++++++++++++++++++--------------------- 1 file changed, 39 insertions(+), 29 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 431839b..609db97 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2240,39 +2240,49 @@ 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 -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html