diff options
Diffstat (limited to 'include/linux/usb/composite.h')
| -rw-r--r-- | include/linux/usb/composite.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h index 6014340ba980..af3cd2aae4bc 100644 --- a/include/linux/usb/composite.h +++ b/include/linux/usb/composite.h @@ -35,6 +35,14 @@ * are ready. The control transfer will then be kept from completing till * all the function drivers that requested for USB_GADGET_DELAYED_STAUS * invoke usb_composite_setup_continue(). + * + * NOTE: USB_GADGET_DELAYED_STATUS must not be used in UDC drivers: they + * must delay completing the status stage for 0-length control transfers + * regardless of the whether USB_GADGET_DELAYED_STATUS is returned from + * the gadget driver's setup() callback. + * Currently, a number of UDC drivers rely on USB_GADGET_DELAYED_STATUS, + * which is a bug. These drivers must be fixed and USB_GADGET_DELAYED_STATUS + * must be contained within the composite framework. */ #define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */ |