in core/hcd.c [478:741]
static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
{
struct usb_ctrlrequest *cmd;
u16 typeReq, wValue, wIndex, wLength;
u8 *ubuf = urb->transfer_buffer;
unsigned len = 0;
int status;
u8 patch_wakeup = 0;
u8 patch_protocol = 0;
u16 tbuf_size;
u8 *tbuf = NULL;
const u8 *bufp;
might_sleep();
spin_lock_irq(&hcd_root_hub_lock);
status = usb_hcd_link_urb_to_ep(hcd, urb);
spin_unlock_irq(&hcd_root_hub_lock);
if (status)
return status;
urb->hcpriv = hcd; /* Indicate it's queued */
cmd = (struct usb_ctrlrequest *) urb->setup_packet;
typeReq = (cmd->bRequestType << 8) | cmd->bRequest;
wValue = le16_to_cpu (cmd->wValue);
wIndex = le16_to_cpu (cmd->wIndex);
wLength = le16_to_cpu (cmd->wLength);
if (wLength > urb->transfer_buffer_length)
goto error;
/*
* tbuf should be at least as big as the
* USB hub descriptor.
*/
tbuf_size = max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
tbuf = kzalloc(tbuf_size, GFP_KERNEL);
if (!tbuf) {
status = -ENOMEM;
goto err_alloc;
}
bufp = tbuf;
urb->actual_length = 0;
switch (typeReq) {
/* DEVICE REQUESTS */
/* The root hub's remote wakeup enable bit is implemented using
* driver model wakeup flags. If this system supports wakeup
* through USB, userspace may change the default "allow wakeup"
* policy through sysfs or these calls.
*
* Most root hubs support wakeup from downstream devices, for
* runtime power management (disabling USB clocks and reducing
* VBUS power usage). However, not all of them do so; silicon,
* board, and BIOS bugs here are not uncommon, so these can't
* be treated quite like external hubs.
*
* Likewise, not all root hubs will pass wakeup events upstream,
* to wake up the whole system. So don't assume root hub and
* controller capabilities are identical.
*/
case DeviceRequest | USB_REQ_GET_STATUS:
tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
<< USB_DEVICE_REMOTE_WAKEUP)
| (1 << USB_DEVICE_SELF_POWERED);
tbuf[1] = 0;
len = 2;
break;
case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
if (wValue == USB_DEVICE_REMOTE_WAKEUP)
device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
else
goto error;
break;
case DeviceOutRequest | USB_REQ_SET_FEATURE:
if (device_can_wakeup(&hcd->self.root_hub->dev)
&& wValue == USB_DEVICE_REMOTE_WAKEUP)
device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
else
goto error;
break;
case DeviceRequest | USB_REQ_GET_CONFIGURATION:
tbuf[0] = 1;
len = 1;
fallthrough;
case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
break;
case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
switch (wValue & 0xff00) {
case USB_DT_DEVICE << 8:
switch (hcd->speed) {
case HCD_USB32:
case HCD_USB31:
bufp = usb31_rh_dev_descriptor;
break;
case HCD_USB3:
bufp = usb3_rh_dev_descriptor;
break;
case HCD_USB25:
bufp = usb25_rh_dev_descriptor;
break;
case HCD_USB2:
bufp = usb2_rh_dev_descriptor;
break;
case HCD_USB11:
bufp = usb11_rh_dev_descriptor;
break;
default:
goto error;
}
len = 18;
if (hcd->has_tt)
patch_protocol = 1;
break;
case USB_DT_CONFIG << 8:
switch (hcd->speed) {
case HCD_USB32:
case HCD_USB31:
case HCD_USB3:
bufp = ss_rh_config_descriptor;
len = sizeof ss_rh_config_descriptor;
break;
case HCD_USB25:
case HCD_USB2:
bufp = hs_rh_config_descriptor;
len = sizeof hs_rh_config_descriptor;
break;
case HCD_USB11:
bufp = fs_rh_config_descriptor;
len = sizeof fs_rh_config_descriptor;
break;
default:
goto error;
}
if (device_can_wakeup(&hcd->self.root_hub->dev))
patch_wakeup = 1;
break;
case USB_DT_STRING << 8:
if ((wValue & 0xff) < 4)
urb->actual_length = rh_string(wValue & 0xff,
hcd, ubuf, wLength);
else /* unsupported IDs --> "protocol stall" */
goto error;
break;
case USB_DT_BOS << 8:
goto nongeneric;
default:
goto error;
}
break;
case DeviceRequest | USB_REQ_GET_INTERFACE:
tbuf[0] = 0;
len = 1;
fallthrough;
case DeviceOutRequest | USB_REQ_SET_INTERFACE:
break;
case DeviceOutRequest | USB_REQ_SET_ADDRESS:
/* wValue == urb->dev->devaddr */
dev_dbg (hcd->self.controller, "root hub device address %d\n",
wValue);
break;
/* INTERFACE REQUESTS (no defined feature/status flags) */
/* ENDPOINT REQUESTS */
case EndpointRequest | USB_REQ_GET_STATUS:
/* ENDPOINT_HALT flag */
tbuf[0] = 0;
tbuf[1] = 0;
len = 2;
fallthrough;
case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
case EndpointOutRequest | USB_REQ_SET_FEATURE:
dev_dbg (hcd->self.controller, "no endpoint features yet\n");
break;
/* CLASS REQUESTS (and errors) */
default:
nongeneric:
/* non-generic request */
switch (typeReq) {
case GetHubStatus:
len = 4;
break;
case GetPortStatus:
if (wValue == HUB_PORT_STATUS)
len = 4;
else
/* other port status types return 8 bytes */
len = 8;
break;
case GetHubDescriptor:
len = sizeof (struct usb_hub_descriptor);
break;
case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
/* len is returned by hub_control */
break;
}
status = hcd->driver->hub_control (hcd,
typeReq, wValue, wIndex,
tbuf, wLength);
if (typeReq == GetHubDescriptor)
usb_hub_adjust_deviceremovable(hcd->self.root_hub,
(struct usb_hub_descriptor *)tbuf);
break;
error:
/* "protocol stall" on error */
status = -EPIPE;
}
if (status < 0) {
len = 0;
if (status != -EPIPE) {
dev_dbg (hcd->self.controller,
"CTRL: TypeReq=0x%x val=0x%x "
"idx=0x%x len=%d ==> %d\n",
typeReq, wValue, wIndex,
wLength, status);
}
} else if (status > 0) {
/* hub_control may return the length of data copied. */
len = status;
status = 0;
}
if (len) {
if (urb->transfer_buffer_length < len)
len = urb->transfer_buffer_length;
urb->actual_length = len;
/* always USB_DIR_IN, toward host */
memcpy (ubuf, bufp, len);
/* report whether RH hardware supports remote wakeup */
if (patch_wakeup &&
len > offsetof (struct usb_config_descriptor,
bmAttributes))
((struct usb_config_descriptor *)ubuf)->bmAttributes
|= USB_CONFIG_ATT_WAKEUP;
/* report whether RH hardware has an integrated TT */
if (patch_protocol &&
len > offsetof(struct usb_device_descriptor,
bDeviceProtocol))
((struct usb_device_descriptor *) ubuf)->
bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
}
kfree(tbuf);
err_alloc:
/* any errors get returned through the urb completion */
spin_lock_irq(&hcd_root_hub_lock);
usb_hcd_unlink_urb_from_ep(hcd, urb);
usb_hcd_giveback_urb(hcd, urb, status);
spin_unlock_irq(&hcd_root_hub_lock);
return 0;
}