/*
* QEMU USB emulation
*
* Copyright (c) 2005 Fabrice Bellard
*
* 2008 Generic packet handler rewrite by Max Krasnyansky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/usb.h"
#include "qemu/iov.h"
#include "trace.h"
void usb_pick_speed(USBPort *port)
{
static const int speeds[] = {
USB_SPEED_SUPER,
USB_SPEED_HIGH,
USB_SPEED_FULL,
USB_SPEED_LOW,
};
USBDevice *udev = port->dev;
int i;
for (i = 0; i < ARRAY_SIZE(speeds); i++) {
if ((udev->speedmask & (1 << speeds[i])) &&
(port->speedmask & (1 << speeds[i]))) {
udev->speed = speeds[i];
return;
}
}
}
void usb_attach(USBPort *port)
{
USBDevice *dev = port->dev;
assert(dev != NULL);
assert(dev->attached);
assert(dev->state == USB_STATE_NOTATTACHED);
usb_pick_speed(port);
port->ops->attach(port);
dev->state = USB_STATE_ATTACHED;
usb_device_handle_attach(dev);
}
void usb_detach(USBPort *port)
{
USBDevice *dev = port->dev;
assert(dev != NULL);
assert(dev->state != USB_STATE_NOTATTACHED);
port->ops->detach(port);
dev->state = USB_STATE_NOTATTACHED;
}
void usb_port_reset(USBPort *port)
{
USBDevice *dev = port->dev;
assert(dev != NULL);
usb_detach(port);
usb_attach(port);
usb_device_reset(dev);
}
void usb_device_reset(USBDevice *dev)
{
if (dev == NULL || !dev->attached) {
return;
}
usb_device_handle_reset(dev);
dev->remote_wakeup = 0;
dev->addr = 0;
dev->state = USB_STATE_DEFAULT;
}
void usb_wakeup(USBEndpoint *ep, unsigned int stream)
{
USBDevice *dev = ep->dev;
USBBus *bus = usb_bus_from_device(dev);
if (!phase_check(PHASE_MACHINE_READY)) {
/*
* This is machine init cold plug. No need to wakeup anyone,
* all devices will be reset anyway. And trying to wakeup can
* cause problems due to hitting uninitialized devices.
*/
return;
}
if (dev->remote_wakeup && dev->port && dev->port->ops->wakeup) {
dev->port->ops->wakeup(dev->port);
}
if (bus->ops->wakeup_endpoint) {
bus->ops->wakeup_endpoint(bus, ep, stream);
}
}
/**********************/
/* generic USB device helpers (you are not forced to use them when
writing your USB device driver, but they help handling the
protocol)
*/
#define SETUP_STATE_IDLE 0
#define SETUP_STATE_SETUP 1
#define SETUP_STATE_DATA 2
#define SETUP_STATE_ACK 3
#define SETUP_STATE_PARAM 4
static void do_token_setup(USBDevice *s, USBPacket *p)
{
int request, value, index;
unsigned int setup_len;
if (p->iov.size != 8) {
p->status = USB_RET_STALL;
return;
}
usb_packet_copy(p, s->setup_buf, p->iov.size);
s->setup_index = 0;
p->actual_length = 0;
setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
if (setup_len > sizeof(s->data_buf)) {
fprintf(stderr,
"usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
setup_len, sizeof(s->data_buf));
p->status = USB_RET_STALL;
return;
}
s->setup_len = setup_len;
request = (s->setup_buf[0] << 8) | s->setup_buf[1];
value = (s->setup_buf[3] << 8) | s->setup_buf[2];
index = (s->setup_buf[5] << 8) | s->setup_buf[4];
if (s->setup_buf[0] & USB_DIR_IN) {
usb_device_handle_control(s, p, request, value, index,
s->setup_len, s->data_buf);
if (p->status == USB_RET_ASYNC) {
s->setup_state = SETUP_STATE_SETUP;
}
if (p->status != USB_RET_SUCCESS) {
return;
}
if (p->actual_length < s->setup_len) {
s->setup_len = p->actual_length;
}
s->setup_state = SETUP_STATE_DATA;
} else {
if (s->setup_len == 0)
s->setup_state = SETUP_STATE_ACK;
else
s->setup_state = SETUP_STATE_DATA;
}
p->actual_length = 8;
}
static void do_token_in(USBDevice *s, USBPacket *p)
{
int request, value, index;
assert(p->ep->nr == 0);
request = (s->setup_buf[0] << 8) | s->setup_buf[1];
value = (s->setup_buf[3] << 8) | s->setup_buf[2];
index = (s->setup_buf[5] << 8) | s->setup_buf[4];
switch(s->setup_state) {
case SETUP_STATE_ACK:
if (!(s->setup_buf[0] & USB_DIR_IN)) {
usb_device_handle_control(s, p, request, value, index,
s->setup_len, s->data_buf);
if (p->status == USB_RET_ASYNC) {
return;
}
s->setup_state = SETUP_STATE_IDLE;
p->actual_length = 0;
}
break;
case SETUP_STATE_DATA:
if (s->setup_buf[0] & USB_DIR_IN) {
int len = s->setup_len - s->setup_index;
if (len > p->iov.size) {
len = p->iov.size;
}
usb_packet_copy(p, s->data_buf + s->setup_index, len);
s->setup_index += len;
if (s->setup_index >= s->setup_len) {
s->setup_state = SETUP_STATE_ACK;
}
return;
}
s->setup_state = SETUP_STATE_IDLE;
p->status = USB_RET_STALL;
break;
default:
p->status = USB_RET_STALL;
}
}
static void do_token_out(USBDevice *s, USBPacket *p)
{
assert(p->ep->nr == 0);
switch(s->setup_state) {
case SETUP_STATE_ACK:
if (s->setup_buf[0] & USB_DIR_IN) {
s->setup_state = SETUP_STATE_IDLE;
/* transfer OK */
} else {
/* ignore additional output */
}
break;
case SETUP_STATE_DATA:
if (!(s->setup_buf[0] & USB_DIR_IN)) {
int len = s->setup_len - s->setup_index;
if (len > p->iov.size) {
len = p->iov.size;
}
usb_packet_copy(p, s->data_buf + s->setup_index, len);
s->setup_index += len;
if (s->setup_index >= s->setup_len) {
s->setup_state = SETUP_STATE_ACK;
}
return;
}
s->setup_state = SETUP_STATE_IDLE;
p->status = USB_RET_STALL;
break;
default:
p->status = USB_RET_STALL;
}
}
static void do_parameter(USBDevice *s, USBPacket *p)
{
int i, request, value, index;
unsigned int setup_len;
for (i = 0; i < 8; i++) {
s->setup_buf[i] = p->parameter >> (i*8);
}
s->setup_state = SETUP_STATE_PARAM;
s->setup_index = 0;
request = (s->setup_buf[0] << 8) | s->setup_buf[1];
value = (s->setup_buf[3] << 8) | s->setup_buf[2];
index = (s->setup_buf[5] << 8) | s->setup_buf[4];
setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
if (setup_len > sizeof(s->data_buf)) {
fprintf(stderr,
"usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
setup_len, sizeof(s->data_buf));
p->status = USB_RET_STALL;
return;
}
s->setup_len = setup_len;
if (p->pid == USB_TOKEN_OUT) {
usb_packet_copy(p, s->data_buf, s->setup_len);
}
usb_device_handle_control(s, p, request, value, index,
s->setup_len, s->data_buf);
if (p->status == USB_RET_ASYNC) {
return;
}
if (p->actual_length < s->setup_len) {
s->setup_len = p->actual_length;
}
if (p->pid == USB_TOKEN_IN) {
p->actual_length = 0;
usb_packet_copy(p, s->data_buf, s->setup_len);
}
}
/* ctrl complete function for devices which use usb_generic_handle_packet and
may return USB_RET_ASYNC from their handle_control callback. Device code
which does this *must* call this function instead of the normal
usb_packet_complete to complete their async control packets. */
void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p)
{
if (p->status < 0) {
s->setup_state = SETUP_STATE_IDLE;
}
switch (s->setup_state) {
case SETUP_STATE_SETUP:
if (p->actual_length < s->setup_len) {
s->setup_len = p->actual_length;
}
s->setup_state = SETUP_STATE_DATA;
p->actual_length = 8;
break;
case SETUP_STATE_ACK:
s->setup_state = SETUP_STATE_IDLE;
p->actual_length = 0;
break;
case SETUP_STATE_PARAM:
if (p->actual_length < s->setup_len) {
s->setup_len = p->actual_length;
}
if (p->pid == USB_TOKEN_IN) {
p->actual_length = 0;
usb_packet_copy(p, s->data_buf, s->setup_len);
}
break;
default:
break;
}
usb_packet_complete(s, p);
}
USBDevice *usb_find_device(USBPort *port, uint8_t addr)
{
USBDevice *dev = port->dev;
if (dev == NULL || !dev->attached || dev->state != USB_STATE_DEFAULT) {
return NULL;
}
if (dev->addr == addr) {
return dev;
}
return usb_device_find_device(dev, addr);
}
static void usb_process_one(USBPacket *p)
{
USBDevice *dev = p->ep->dev;
/*
* Handlers expect status to be initialized to USB_RET_SUCCESS, but it
* can be USB_RET_NAK here from a previous usb_process_one() call,
* or USB_RET_ASYNC from going through usb_queue_one().
*/
p->status = USB_RET_SUCCESS;
if (p->ep->nr == 0) {
/* control pipe */
if (p->parameter) {
do_parameter(dev, p);
return;
}
switch (p->pid) {
case USB_TOKEN_SETUP:
do_token_setup(dev, p);
break;
case USB_TOKEN_IN:
do_token_in(dev, p);
break;
case USB_TOKEN_OUT:
do_token_out(dev, p);
break;
default:
p->status = USB_RET_STALL;
}
} else {
/* data pipe */
usb_device_handle_data(dev, p);
}
}
static void usb_queue_one(USBPacket *p)
{
usb_packet_set_state(p, USB_PACKET_QUEUED);
QTAILQ_INSERT_TAIL(&p->ep->queue, p, queue);
p->status = USB_RET_ASYNC;
}
/* Hand over a packet to a device for processing. p->status ==
USB_RET_ASYNC indicates the processing isn't finished yet, the
driver will call usb_packet_complete() when done processing it. */
void usb_handle_packet(USBDevice *dev, USBPacket *p)
{
if (dev == NULL) {
p->status = USB_RET_NODEV;
return;
}
assert(dev == p->ep->dev);
assert(dev->state == USB_STATE_DEFAULT);
usb_packet_check_state(p, USB_PACKET_SETUP);
assert(p->ep != NULL);
/* Submitting a new packet clears halt */
if (p->ep->halted) {
assert(QTAILQ_EMPTY(&p->ep->queue));
p->ep->halted = false;
}
if (QTAILQ_EMPTY(&p->ep->queue) || p->ep->pipeline || p->stream) {
usb_process_one(p);
if (p->status == USB_RET_ASYNC) {
/* hcd drivers cannot handle async for isoc */
assert(p->ep->type != USB_ENDPOINT_XFER_ISOC);
/* using async for interrupt packets breaks migration */
assert(p->ep->type != USB_ENDPOINT_XFER_INT ||
(dev->flags & (1 << USB_DEV_FLAG_IS_HOST)));
usb_packet_set_state(p, USB_PACKET_ASYNC);
QTAILQ_INSERT_TAIL(&p->ep->queue, p, queue);
} else if (p->status == USB_RET_ADD_TO_QUEUE) {
usb_queue_one(p);
} else {
/*
* When pipelining is enabled usb-devices must always return async,
* otherwise packets can complete out of order!
*/
assert(p->stream || !p->ep->pipeline ||
QTAILQ_EMPTY(&p->ep->queue));
if (p->status != USB_RET_NAK) {
usb_packet_set_state(p, USB_PACKET_COMPLETE);
}
}
} else {
usb_queue_one(p);
}
}
void usb_packet_complete_one(USBDevice *dev, USBPacket *p)
{
USBEndpoint *ep = p->ep;
assert(p->stream || QTAILQ_FIRST(&ep->queue) == p);
assert(p->status != USB_RET_ASYNC && p->status != USB_RET_NAK);
if (p->status != USB_RET_SUCCESS ||
(p->short_not_ok && (p->actual_length < p->iov.size))) {
ep->halted = true;
}
usb_packet_set_state(p, USB_PACKET_COMPLETE);
QTAILQ_REMOVE(&ep->queue, p, queue);
dev->port->ops->complete(dev->port, p);
}
/* Notify the controller that an async packet is complete. This should only
be called for packets previously deferred by returning USB_RET_ASYNC from
handle_packet. */
void usb_packet_complete(USBDevice *dev, USBPacket *p)
{
USBEndpoint *ep = p->ep;
usb_packet_check_state(p, USB_PACKET_ASYNC);
usb_packet_complete_one(dev, p);
while (!QTAILQ_EMPTY(&ep->queue)) {
p = QTAILQ_FIRST(&ep->queue);
if (ep->halted) {
/* Empty the queue on a halt */
p->status = USB_RET_REMOVE_FROM_QUEUE;
dev->port->ops->complete(dev->port, p);
continue;
}
if (p->state == USB_PACKET_ASYNC) {
break;
}
usb_packet_check_state(p, USB_PACKET_QUEUED);
usb_process_one(p);
if (p->status == USB_RET_ASYNC) {
usb_packet_set_state(p, USB_PACKET_ASYNC);
break;
}
usb_packet_complete_one(ep->dev, p);
}
}
/* Cancel an active packet. The packed must have been deferred by
returning USB_RET_ASYNC from handle_packet, and not yet
completed. */
void usb_cancel_packet(USBPacket * p)
{
bool callback = (p->state == USB_PACKET_ASYNC);
assert(usb_packet_is_inflight(p));
usb_packet_set_state(p, USB_PACKET_CANCELED);
QTAILQ_REMOVE(&p->ep->queue, p, queue);
if (callback) {
usb_device_cancel_packet(p->ep->dev, p);
}
}
void usb_packet_init(USBPacket *p)
{
qemu_iovec_init(&p->iov, 1);
}
static const char *usb_packet_state_name(USBPacketState state)
{
static const char *name[] = {
[USB_PACKET_UNDEFINED] = "undef",
[USB_PACKET_SETUP] = "setup",
[USB_PACKET_QUEUED] = "queued",
[USB_PACKET_ASYNC] = "async",
[USB_PACKET_COMPLETE] = "complete",
[USB_PACKET_CANCELED] = "canceled",
};
if (state < ARRAY_SIZE(name)) {
return name[state];
}
return "INVALID";
}
void usb_packet_check_state(USBPacket *p, USBPacketState expected)
{
USBDevice *dev;
USBBus *bus;
if (p->state == expected) {
return;
}
dev = p->ep->dev;
bus = usb_bus_from_device(dev);
trace_usb_packet_state_fault(bus->busnr, dev->port->path, p->ep->nr, p,
usb_packet_state_name(p->state),
usb_packet_state_name(expected));
assert(!"usb packet state check failed");
}
void usb_packet_set_state(USBPacket *p, USBPacketState state)
{
if (p->ep) {
USBDevice *dev = p->ep->dev;
USBBus *bus = usb_bus_from_device(dev);
trace_usb_packet_state_change(bus->busnr, dev->port->path, p->ep->nr, p,
usb_packet_state_name(p->state),
usb_packet_state_name(state));
} else {
trace_usb_packet_state_change(-1, "", -1, p,
usb_packet_state_name(p->state),
usb_packet_state_name(state));
}
p->state = state;
}
void usb_packet_setup(USBPacket *p, int pid,
USBEndpoint *ep, unsigned int stream,
uint64_t id, bool short_not_ok, bool int_req)
{
assert(!usb_packet_is_inflight(p));
assert(p->iov.iov != NULL);
p->id = id;
p->pid = pid;
p->ep = ep;
p->stream = stream;
p->status = USB_RET_SUCCESS;
p->actual_length = 0;
p->parameter = 0;
p->short_not_ok = short_not_ok;
p->int_req = int_req;
p->combined = NULL;
qemu_iovec_reset(&p->iov);
usb_packet_set_state(p, USB_PACKET_SETUP);
}
void usb_packet_addbuf(USBPacket *p, void *ptr, size_t len)
{
qemu_iovec_add(&p->iov, ptr, len);
}
void usb_packet_copy(USBPacket *p, void *ptr, size_t bytes)
{
QEMUIOVector *iov = p->combined ? &p->combined->iov : &p->iov;
assert(p->actual_length >= 0);
assert(p->actual_length + bytes <= iov->size);
switch (p->pid) {
case USB_TOKEN_SETUP:
case USB_TOKEN_OUT:
iov_to_buf(iov->iov, iov->niov, p->actual_length, ptr, bytes);
break;
case USB_TOKEN_IN:
iov_from_buf(iov->iov, iov->niov, p->actual_length, ptr, bytes);
break;
default:
fprintf(stderr, "%s: invalid pid: %x\n", __func__, p->pid);
abort();
}
p->actual_length += bytes;
}
void usb_packet_skip(USBPacket *p, size_t bytes)
{
QEMUIOVector *iov = p->combined ? &p->combined->iov : &p->iov;
assert(p->actual_length >= 0);
assert(p->actual_length + bytes <= iov->size);
if (p->pid == USB_TOKEN_IN) {
iov_memset(iov->iov, iov->niov, p->actual_length, 0, bytes);
}
p->actual_length += bytes;
}
size_t usb_packet_size(USBPacket *p)
{
return p->combined ? p->combined->iov.size : p->iov.size;
}
void usb_packet_cleanup(USBPacket *p)
{
assert(!usb_packet_is_inflight(p));
qemu_iovec_destroy(&p->iov);
}
void usb_ep_reset(USBDevice *dev)
{
int ep;
dev->ep_ctl.nr = 0;
dev->ep_ctl.type = USB_ENDPOINT_XFER_CONTROL;
dev->ep_ctl.ifnum = 0;
dev->ep_ctl.max_packet_size = 64;
dev->ep_ctl.max_streams = 0;
dev->ep_ctl.dev = dev;
dev->ep_ctl.pipeline = false;
for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
dev->ep_in[ep].nr = ep + 1;
dev->ep_out[ep].nr = ep + 1;
dev->ep_in[ep].pid = USB_TOKEN_IN;
dev->ep_out[ep].pid = USB_TOKEN_OUT;
dev->ep_in[ep].type = USB_ENDPOINT_XFER_INVALID;
dev->ep_out[ep].type = USB_ENDPOINT_XFER_INVALID;
dev->ep_in[ep].ifnum = USB_INTERFACE_INVALID;
dev->ep_out[ep].ifnum = USB_INTERFACE_INVALID;
dev->ep_in[ep].max_packet_size = 0;
dev->ep_out[ep].max_packet_size = 0;
dev->ep_in[ep].max_streams = 0;
dev->ep_out[ep].max_streams = 0;
dev->ep_in[ep].dev = dev;
dev->ep_out[ep].dev = dev;
dev->ep_in[ep].pipeline = false;
dev->ep_out[ep].pipeline = false;
}
}
void usb_ep_init(USBDevice *dev)
{
int ep;
usb_ep_reset(dev);
QTAILQ_INIT(&dev->ep_ctl.queue);
for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
QTAILQ_INIT(&dev->ep_in[ep].queue);
QTAILQ_INIT(&dev->ep_out[ep].queue);
}
}
void usb_ep_dump(USBDevice *dev)
{
static const char *tname[] = {
[USB_ENDPOINT_XFER_CONTROL] = "control",
[USB_ENDPOINT_XFER_ISOC] = "isoc",
[USB_ENDPOINT_XFER_BULK] = "bulk",
[USB_ENDPOINT_XFER_INT] = "int",
};
int ifnum, ep, first;
fprintf(stderr, "Device \"%s\", config %d\n",
dev->product_desc, dev->configuration);
for (ifnum = 0; ifnum < 16; ifnum++) {
first = 1;
for (ep = 0; ep < USB_MAX_ENDPOINTS; ep++) {
if (dev->ep_in[ep].type != USB_ENDPOINT_XFER_INVALID &&
dev->ep_in[ep].ifnum == ifnum) {
if (first) {
first = 0;
fprintf(stderr, " Interface %d, alternative %d\n",
ifnum, dev->altsetting[ifnum]);
}
fprintf(stderr, " Endpoint %d, IN, %s, %d max\n", ep,
tname[dev->ep_in[ep].type],
dev->ep_in[ep].max_packet_size);
}
if (dev->ep_out[ep].type != USB_ENDPOINT_XFER_INVALID &&
dev->ep_out[ep].ifnum == ifnum) {
if (first) {
first = 0;
fprintf(stderr, " Interface %d, alternative %d\n",
ifnum, dev->altsetting[ifnum]);
}
fprintf(stderr, " Endpoint %d, OUT, %s, %d max\n", ep,
tname[dev->ep_out[ep].type],
dev->ep_out[ep].max_packet_size);
}
}
}
fprintf(stderr, "--\n");
}
struct USBEndpoint *usb_ep_get(USBDevice *dev, int pid, int ep)
{
struct USBEndpoint *eps;
assert(dev != NULL);
if (ep == 0) {
return &dev->ep_ctl;
}
assert(pid == USB_TOKEN_IN || pid == USB_TOKEN_OUT);
assert(ep > 0 && ep <= USB_MAX_ENDPOINTS);
eps = (pid == USB_TOKEN_IN) ? dev->ep_in : dev->ep_out;
return eps + ep - 1;
}
uint8_t usb_ep_get_type(USBDevice *dev, int pid, int ep)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
return uep->type;
}
void usb_ep_set_type(USBDevice *dev, int pid, int ep, uint8_t type)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
uep->type = type;
}
void usb_ep_set_ifnum(USBDevice *dev, int pid, int ep, uint8_t ifnum)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
uep->ifnum = ifnum;
}
void usb_ep_set_max_packet_size(USBDevice *dev, int pid, int ep,
uint16_t raw)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
int size, microframes;
size = raw & 0x7ff;
switch ((raw >> 11) & 3) {
case 1:
microframes = 2;
break;
case 2:
microframes = 3;
break;
default:
microframes = 1;
break;
}
uep->max_packet_size = size * microframes;
}
void usb_ep_set_max_streams(USBDevice *dev, int pid, int ep, uint8_t raw)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
int MaxStreams;
MaxStreams = raw & 0x1f;
if (MaxStreams) {
uep->max_streams = 1 << MaxStreams;
} else {
uep->max_streams = 0;
}
}
void usb_ep_set_halted(USBDevice *dev, int pid, int ep, bool halted)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
uep->halted = halted;
}
USBPacket *usb_ep_find_packet_by_id(USBDevice *dev, int pid, int ep,
uint64_t id)
{
struct USBEndpoint *uep = usb_ep_get(dev, pid, ep);
USBPacket *p;
QTAILQ_FOREACH(p, &uep->queue, queue) {
if (p->id == id) {
return p;
}
}
return NULL;
}
