diff options
| -rw-r--r-- | include/linux/usb.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h index 475cb75cc37..112a2d6e922 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1044,7 +1044,9 @@ typedef void (*usb_complete_t)(struct urb *); * @setup_dma: For control transfers with URB_NO_SETUP_DMA_MAP set, the * device driver has provided this DMA address for the setup packet. * The host controller driver should use this in preference to - * setup_packet. + * setup_packet, but the HCD may chose to ignore the address if it must + * copy the setup packet into internal structures. Therefore, setup_packet + * must always point to a valid buffer. * @start_frame: Returns the initial frame for isochronous transfers. * @number_of_packets: Lists the number of ISO transfer buffers. * @interval: Specifies the polling interval for interrupt or isochronous |