diff options
Diffstat (limited to 'src/include/ipxe/usb.h')
| -rw-r--r-- | src/include/ipxe/usb.h | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/src/include/ipxe/usb.h b/src/include/ipxe/usb.h index e961f7480..a9c185f6c 100644 --- a/src/include/ipxe/usb.h +++ b/src/include/ipxe/usb.h @@ -1178,20 +1178,42 @@ extern unsigned int usb_route_string ( struct usb_device *usb ); extern unsigned int usb_depth ( struct usb_device *usb ); extern struct usb_port * usb_root_hub_port ( struct usb_device *usb ); -/** Minimum reset time */ +/** Minimum reset time + * + * Section 7.1.7.5 of the USB2 specification states that root hub + * ports should assert reset signalling for at least 50ms. + */ #define USB_RESET_DELAY_MS 50 +/** Reset recovery time + * + * Section 9.2.6.2 of the USB2 specification states that the + * "recovery" interval after a port reset is 10ms. + */ +#define USB_RESET_RECOVER_DELAY_MS 10 + /** Maximum time to wait for a control transaction to complete * - * This is a policy decision. + * Section 9.2.6.1 of the USB2 specification states that the upper + * limit for commands to be processed is 5 seconds. + */ +#define USB_CONTROL_MAX_WAIT_MS 5000 + +/** Set address recovery time + * + * Section 9.2.6.3 of the USB2 specification states that devices are + * allowed a 2ms recovery interval after receiving a new address. */ -#define USB_CONTROL_MAX_WAIT_MS 100 +#define USB_SET_ADDRESS_RECOVER_DELAY_MS 2 /** Time to wait for ports to stabilise * - * This is a policy decision. + * Section 7.1.7.3 of the USB specification states that we must allow + * 100ms for devices to signal attachment, and an additional 100ms for + * connection debouncing. (This delay is parallelised across all + * ports on a hub; we do not delay separately for each port.) */ -#define USB_PORT_DELAY_MS 100 +#define USB_PORT_DELAY_MS 200 /** A USB device ID */ struct usb_device_id { |