diff options
Diffstat (limited to 'drivers/usb/core/message.c')
| -rw-r--r-- | drivers/usb/core/message.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index dac4adeec213..c64cf6c4a83d 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -916,6 +916,30 @@ int usb_get_device_descriptor(struct usb_device *dev, unsigned int size) return ret; } +/* + * usb_set_isoch_delay - informs the device of the packet transmit delay + * @dev: the device whose delay is to be informed + * Context: !in_interrupt() + * + * Since this is an optional request, we don't bother if it fails. + */ +int usb_set_isoch_delay(struct usb_device *dev) +{ + /* skip hub devices */ + if (dev->descriptor.bDeviceClass == USB_CLASS_HUB) + return 0; + + /* skip non-SS/non-SSP devices */ + if (dev->speed < USB_SPEED_SUPER) + return 0; + + return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), + USB_REQ_SET_ISOCH_DELAY, + USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE, + cpu_to_le16(dev->hub_delay), 0, NULL, 0, + USB_CTRL_SET_TIMEOUT); +} + /** * usb_get_status - issues a GET_STATUS call * @dev: the device whose status is being checked |