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[ncm] Use generic refill framework for bulk IN and interrupt endpoints 

Signed-off-by: Michael Brown <mcb30@ipxe.org>
pull/34/head
Michael Brown 2015-02-12 15:17:21 +00:00
parent 1706ab7ff3
commit 14fc311271
2 changed files with 92 additions and 252 deletions
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304
src/drivers/net/ncm.c
View File

@ -35,10 +35,6 @@ FILE_LICENCE ( GPL2_OR_LATER );
*
*/
/** Ring refill profiler */
static struct profiler ncm_refill_profiler __profiler =
{ .name = "ncm.refill" };
/** Interrupt completion profiler */
static struct profiler ncm_intr_profiler __profiler =
{ .name = "ncm.intr" };
@ -55,144 +51,6 @@ static struct profiler ncm_in_datagram_profiler __profiler =
static struct profiler ncm_out_profiler __profiler =
{ .name = "ncm.out" };
/******************************************************************************
*
* Ring management
*
******************************************************************************
*/
/**
* Transcribe receive ring name (for debugging)
*
* @v ncm CDC-NCM device
* @v ring Receive ring
* @ret name Receive ring name
*/
static inline const char * ncm_rx_name ( struct ncm_device *ncm,
struct ncm_rx_ring *ring ) {
if ( ring == &ncm->intr ) {
return "interrupt";
} else if ( ring == &ncm->in ) {
return "bulk IN";
} else {
return "UNKNOWN";
}
}
/**
* Allocate receive ring buffers
*
* @v ncm CDC-NCM device
* @v ring Receive ring
* @v mtu I/O buffer size
* @v count Number of I/O buffers
* @ret rc Return status code
*/
static int ncm_rx_alloc ( struct ncm_device *ncm, struct ncm_rx_ring *ring,
size_t mtu, unsigned int count ) {
struct io_buffer *iobuf;
struct io_buffer *tmp;
unsigned int i;
int rc;
/* Initialise ring */
ring->mtu = mtu;
INIT_LIST_HEAD ( &ring->list );
/* Allocate I/O buffers */
for ( i = 0 ; i < count ; i++ ) {
iobuf = alloc_iob ( mtu );
if ( ! iobuf ) {
DBGC ( ncm, "NCM %p could not allocate %dx %zd-byte "
"buffers for %s\n", ncm, count, mtu,
ncm_rx_name ( ncm, ring ) );
rc = -ENOMEM;
goto err_alloc;
}
list_add ( &iobuf->list, &ring->list );
}
return 0;
err_alloc:
list_for_each_entry_safe ( iobuf, tmp, &ring->list, list ) {
list_del ( &iobuf->list );
free_iob ( iobuf );
}
return rc;
}
/**
* Refill receive ring
*
* @v ncm CDC-NCM device
* @v ring Receive ring
* @ret rc Return status code
*/
static int ncm_rx_refill ( struct ncm_device *ncm, struct ncm_rx_ring *ring ) {
struct io_buffer *iobuf;
int rc;
/* Enqueue any recycled I/O buffers */
while ( ( iobuf = list_first_entry ( &ring->list, struct io_buffer,
list ) ) ) {
/* Profile refill */
profile_start ( &ncm_refill_profiler );
/* Reset size */
iob_put ( iobuf, ( ring->mtu - iob_len ( iobuf ) ) );
/* Enqueue I/O buffer */
if ( ( rc = usb_stream ( &ring->ep, iobuf, 0 ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not enqueue %s: %s\n", ncm,
ncm_rx_name ( ncm, ring ), strerror ( rc ) );
/* Leave in recycled list and wait for next refill */
return rc;
}
/* Remove from recycled list */
list_del ( &iobuf->list );
profile_stop ( &ncm_refill_profiler );
}
return 0;
}
/**
* Recycle receive buffer
*
* @v ncm CDC-NCM device
* @v ring Receive ring
* @v iobuf I/O buffer
*/
static inline void ncm_rx_recycle ( struct ncm_device *ncm __unused,
struct ncm_rx_ring *ring,
struct io_buffer *iobuf ) {
/* Add to recycled list */
list_add_tail ( &iobuf->list, &ring->list );
}
/**
* Free receive ring
*
* @v ncm CDC-NCM device
* @v ring Receive ring
*/
static void ncm_rx_free ( struct ncm_device *ncm __unused,
struct ncm_rx_ring *ring ) {
struct io_buffer *iobuf;
struct io_buffer *tmp;
/* Free I/O buffers */
list_for_each_entry_safe ( iobuf, tmp, &ring->list, list ) {
list_del ( &iobuf->list );
free_iob ( iobuf );
}
}
/******************************************************************************
*
* CDC-NCM communications interface
@ -209,7 +67,7 @@ static void ncm_rx_free ( struct ncm_device *ncm __unused,
*/
static void ncm_intr_complete ( struct usb_endpoint *ep,
struct io_buffer *iobuf, int rc ) {
struct ncm_device *ncm = container_of ( ep, struct ncm_device, intr.ep);
struct ncm_device *ncm = container_of ( ep, struct ncm_device, intr );
struct net_device *netdev = ncm->netdev;
struct usb_setup_packet *message;
size_t len = iob_len ( iobuf );
@ -219,21 +77,22 @@ static void ncm_intr_complete ( struct usb_endpoint *ep,
/* Ignore packets cancelled when the endpoint closes */
if ( ! ep->open )
goto done;
goto ignore;
/* Ignore packets with errors */
if ( rc != 0 ) {
DBGC ( ncm, "NCM %p interrupt failed: %s\n",
ncm, strerror ( rc ) );
DBGC_HDA ( ncm, 0, iobuf->data, iob_len ( iobuf ) );
goto done;
goto error;
}
/* Extract message header */
if ( len < sizeof ( *message ) ) {
DBGC ( ncm, "NCM %p underlength interrupt:\n", ncm );
DBGC_HDA ( ncm, 0, iobuf->data, iob_len ( iobuf ) );
goto done;
rc = -EINVAL;
goto error;
}
message = iobuf->data;
@ -257,13 +116,20 @@ static void ncm_intr_complete ( struct usb_endpoint *ep,
default:
DBGC ( ncm, "NCM %p unrecognised interrupt:\n", ncm );
DBGC_HDA ( ncm, 0, iobuf->data, iob_len ( iobuf ) );
break;
goto error;
}
done:
/* Recycle buffer */
ncm_rx_recycle ( ncm, &ncm->intr, iobuf );
/* Free I/O buffer */
free_iob ( iobuf );
profile_stop ( &ncm_intr_profiler );
return;
error:
netdev_rx_err ( netdev, iob_disown ( iobuf ), rc );
ignore:
free_iob ( iobuf );
return;
}
/** Interrupt endpoint operations */
@ -280,27 +146,20 @@ static struct usb_endpoint_driver_operations ncm_intr_operations = {
static int ncm_comms_open ( struct ncm_device *ncm ) {
int rc;
/* Allocate I/O buffers */
if ( ( rc = ncm_rx_alloc ( ncm, &ncm->intr, ncm->intr.ep.mtu,
NCM_INTR_COUNT ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not allocate RX buffers: %s\n",
ncm, strerror ( rc ) );
goto err_alloc;
}
/* Open interrupt endpoint */
if ( ( rc = usb_endpoint_open ( &ncm->intr.ep ) ) != 0 ) {
if ( ( rc = usb_endpoint_open ( &ncm->intr ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not open interrupt: %s\n",
ncm, strerror ( rc ) );
goto err_open;
}
/* Refill interrupt endpoint */
usb_refill ( &ncm->intr );
return 0;
usb_endpoint_close ( &ncm->intr.ep );
usb_endpoint_close ( &ncm->intr );
err_open:
ncm_rx_free ( ncm, &ncm->intr );
err_alloc:
return rc;
}
@ -312,10 +171,7 @@ static int ncm_comms_open ( struct ncm_device *ncm ) {
static void ncm_comms_close ( struct ncm_device *ncm ) {
/* Close interrupt endpoint */
usb_endpoint_close ( &ncm->intr.ep );
/* Free I/O buffers */
ncm_rx_free ( ncm, &ncm->intr );
usb_endpoint_close ( &ncm->intr );
}
/******************************************************************************
@ -326,12 +182,12 @@ static void ncm_comms_close ( struct ncm_device *ncm ) {
*/
/**
* Allocate bulk IN receive ring buffers
* Prefill bulk IN endpoint
*
* @v ncm CDC-NCM device
* @ret rc Return status code
*/
static int ncm_in_alloc ( struct ncm_device *ncm ) {
static int ncm_in_prefill ( struct ncm_device *ncm ) {
size_t mtu;
unsigned int count;
int rc;
@ -358,15 +214,19 @@ static int ncm_in_alloc ( struct ncm_device *ncm ) {
count = NCM_IN_MIN_COUNT;
if ( ( count * mtu ) > NCM_IN_MAX_SIZE )
continue;
if ( ( rc = ncm_rx_alloc ( ncm, &ncm->in, mtu, count ) ) != 0 )
usb_refill_init ( &ncm->in, mtu, count );
if ( ( rc = usb_prefill ( &ncm->in ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not prefill %dx %zd-byte "
"buffers for bulk IN\n", ncm, count, mtu );
continue;
}
DBGC ( ncm, "NCM %p using %dx %zd-byte buffers for bulk IN\n",
ncm, count, mtu );
return 0;
}
DBGC ( ncm, "NCM %p could not allocate bulk IN buffers\n", ncm );
DBGC ( ncm, "NCM %p could not prefill bulk IN endpoint\n", ncm );
return -ENOMEM;
}
@ -379,7 +239,7 @@ static int ncm_in_alloc ( struct ncm_device *ncm ) {
*/
static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
int rc ) {
struct ncm_device *ncm = container_of ( ep, struct ncm_device, in.ep );
struct ncm_device *ncm = container_of ( ep, struct ncm_device, in );
struct net_device *netdev = ncm->netdev;
struct ncm_transfer_header *nth;
struct ncm_datagram_pointer *ndp;
@ -404,13 +264,14 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
if ( rc != 0 ) {
DBGC ( ncm, "NCM %p bulk IN failed: %s\n",
ncm, strerror ( rc ) );
goto drop;
goto error;
}
/* Locate transfer header */
len = iob_len ( iobuf );
if ( sizeof ( *nth ) > len ) {
DBGC ( ncm, "NCM %p packet too short for NTH:\n", ncm );
rc = -EINVAL;
goto error;
}
nth = iobuf->data;
@ -419,16 +280,19 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
ndp_offset = le16_to_cpu ( nth->offset );
if ( ( ndp_offset + sizeof ( *ndp ) ) > len ) {
DBGC ( ncm, "NCM %p packet too short for NDP:\n", ncm );
rc = -EINVAL;
goto error;
}
ndp = ( iobuf->data + ndp_offset );
ndp_len = le16_to_cpu ( ndp->header_len );
if ( ndp_len < offsetof ( typeof ( *ndp ), desc ) ) {
DBGC ( ncm, "NCM %p NDP header length too short:\n", ncm );
rc = -EINVAL;
goto error;
}
if ( ( ndp_offset + ndp_len ) > len ) {
DBGC ( ncm, "NCM %p packet too short for NDP:\n", ncm );
rc = -EINVAL;
goto error;
}
@ -445,10 +309,12 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
pkt_len = le16_to_cpu ( desc->len );
if ( pkt_len < ETH_HLEN ) {
DBGC ( ncm, "NCM %p underlength datagram:\n", ncm );
rc = -EINVAL;
goto error;
}
if ( ( pkt_offset + pkt_len ) > len ) {
DBGC ( ncm, "NCM %p datagram exceeds packet:\n", ncm );
rc = -EINVAL;
goto error;
}
@ -468,8 +334,7 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
* received packet and reuse the same I/O buffer for
* transmission.
*/
headroom = ( sizeof ( struct ncm_ntb_header ) +
ncm->out.padding );
headroom = ( sizeof ( struct ncm_ntb_header ) + ncm->padding );
pkt = alloc_iob ( headroom + pkt_len );
if ( ! pkt ) {
/* Record error and continue */
@ -490,19 +355,17 @@ static void ncm_in_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
}
/* Recycle I/O buffer */
ncm_rx_recycle ( ncm, &ncm->in, iobuf );
usb_recycle ( &ncm->in, iobuf );
profile_stop ( &ncm_in_profiler );
return;
error:
rc = -EIO;
drop:
/* Record error against network device */
DBGC_HDA ( ncm, 0, iobuf->data, iob_len ( iobuf ) );
netdev_rx_err ( netdev, NULL, rc );
ignore:
ncm_rx_recycle ( ncm, &ncm->in, iobuf );
usb_recycle ( &ncm->in, iobuf );
}
/** Bulk IN endpoint operations */
@ -521,7 +384,7 @@ static int ncm_out_transmit ( struct ncm_device *ncm,
struct io_buffer *iobuf ) {
struct ncm_ntb_header *header;
size_t len = iob_len ( iobuf );
size_t header_len = ( sizeof ( *header ) + ncm->out.padding );
size_t header_len = ( sizeof ( *header ) + ncm->padding );
int rc;
/* Profile transmissions */
@ -535,7 +398,7 @@ static int ncm_out_transmit ( struct ncm_device *ncm,
/* Populate header */
header->nth.magic = cpu_to_le32 ( NCM_TRANSFER_HEADER_MAGIC );
header->nth.header_len = cpu_to_le16 ( sizeof ( header->nth ) );
header->nth.sequence = cpu_to_le16 ( ncm->out.sequence );
header->nth.sequence = cpu_to_le16 ( ncm->sequence );
header->nth.len = cpu_to_le16 ( iob_len ( iobuf ) );
header->nth.offset =
cpu_to_le16 ( offsetof ( typeof ( *header ), ndp ) );
@ -548,11 +411,11 @@ static int ncm_out_transmit ( struct ncm_device *ncm,
memset ( &header->desc[1], 0, sizeof ( header->desc[1] ) );
/* Enqueue I/O buffer */
if ( ( rc = usb_stream ( &ncm->out.ep, iobuf, 0 ) ) != 0 )
if ( ( rc = usb_stream ( &ncm->out, iobuf, 0 ) ) != 0 )
return rc;
/* Increment sequence number */
ncm->out.sequence++;
ncm->sequence++;
profile_stop ( &ncm_out_profiler );
return 0;
@ -567,7 +430,7 @@ static int ncm_out_transmit ( struct ncm_device *ncm,
*/
static void ncm_out_complete ( struct usb_endpoint *ep, struct io_buffer *iobuf,
int rc ) {
struct ncm_device *ncm = container_of ( ep, struct ncm_device, out.ep );
struct ncm_device *ncm = container_of ( ep, struct ncm_device, out );
struct net_device *netdev = ncm->netdev;
/* Report TX completion */
@ -590,13 +453,13 @@ static int ncm_data_open ( struct ncm_device *ncm ) {
struct ncm_set_ntb_input_size size;
int rc;
/* Allocate I/O buffers */
if ( ( rc = ncm_in_alloc ( ncm ) ) != 0 )
goto err_alloc;
/* Prefill I/O buffers */
if ( ( rc = ncm_in_prefill ( ncm ) ) != 0 )
goto err_prefill;
/* Set maximum input size */
memset ( &size, 0, sizeof ( size ) );
size.mtu = cpu_to_le32 ( ncm->in.mtu );
size.mtu = cpu_to_le32 ( ncm->in.len );
if ( ( rc = usb_control ( usb, NCM_SET_NTB_INPUT_SIZE, 0, ncm->comms,
&size, sizeof ( size ) ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not set input size to %zd: %s\n",
@ -613,33 +476,38 @@ static int ncm_data_open ( struct ncm_device *ncm ) {
}
/* Open bulk IN endpoint */
if ( ( rc = usb_endpoint_open ( &ncm->in.ep ) ) != 0 ) {
if ( ( rc = usb_endpoint_open ( &ncm->in ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not open bulk IN: %s\n",
ncm, strerror ( rc ) );
goto err_open_in;
}
/* Open bulk OUT endpoint */
if ( ( rc = usb_endpoint_open ( &ncm->out.ep ) ) != 0 ) {
if ( ( rc = usb_endpoint_open ( &ncm->out ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not open bulk OUT: %s\n",
ncm, strerror ( rc ) );
goto err_open_out;
}
/* Reset transmit sequence number */
ncm->out.sequence = 0;
/* Refill bulk IN endpoint */
if ( ( rc = usb_refill ( &ncm->in ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not refill bulk IN: %s\n",
ncm, strerror ( rc ) );
goto err_refill;
}
return 0;
usb_endpoint_close ( &ncm->out.ep );
err_refill:
usb_endpoint_close ( &ncm->out );
err_open_out:
usb_endpoint_close ( &ncm->in.ep );
usb_endpoint_close ( &ncm->in );
err_open_in:
usb_set_interface ( usb, ncm->data, 0 );
err_set_interface:
err_set_ntb_input_size:
ncm_rx_free ( ncm, &ncm->in );
err_alloc:
usb_flush ( &ncm->in );
err_prefill:
return rc;
}
@ -652,14 +520,11 @@ static void ncm_data_close ( struct ncm_device *ncm ) {
struct usb_device *usb = ncm->usb;
/* Close endpoints */
usb_endpoint_close ( &ncm->out.ep );
usb_endpoint_close ( &ncm->in.ep );
usb_endpoint_close ( &ncm->out );
usb_endpoint_close ( &ncm->in );
/* Reset data interface */
usb_set_interface ( usb, ncm->data, 0 );
/* Free I/O buffers */
ncm_rx_free ( ncm, &ncm->in );
}
/******************************************************************************
@ -680,30 +545,20 @@ static int ncm_open ( struct net_device *netdev ) {
int rc;
/* Reset sequence number */
ncm->out.sequence = 0;
ncm->sequence = 0;
/* Open communications interface */
if ( ( rc = ncm_comms_open ( ncm ) ) != 0 )
goto err_comms_open;
/* Refill interrupt ring */
if ( ( rc = ncm_rx_refill ( ncm, &ncm->intr ) ) != 0 )
goto err_intr_refill;
/* Open data interface */
if ( ( rc = ncm_data_open ( ncm ) ) != 0 )
goto err_data_open;
/* Refill bulk IN ring */
if ( ( rc = ncm_rx_refill ( ncm, &ncm->in ) ) != 0 )
goto err_in_refill;
return 0;
err_in_refill:
ncm_data_close ( ncm );
err_data_open:
err_intr_refill:
ncm_comms_close ( ncm );
err_comms_open:
return rc;
@ -755,12 +610,12 @@ static void ncm_poll ( struct net_device *netdev ) {
/* Poll USB bus */
usb_poll ( ncm->bus );
/* Refill interrupt ring */
if ( ( rc = ncm_rx_refill ( ncm, &ncm->intr ) ) != 0 )
/* Refill interrupt endpoint */
if ( ( rc = usb_refill ( &ncm->intr ) ) != 0 )
netdev_rx_err ( netdev, NULL, rc );
/* Refill bulk IN ring */
if ( ( rc = ncm_rx_refill ( ncm, &ncm->in ) ) != 0 )
/* Refill bulk IN endpoint */
if ( ( rc = usb_refill ( &ncm->in ) ) != 0 )
netdev_rx_err ( netdev, NULL, rc );
}
@ -810,9 +665,10 @@ static int ncm_probe ( struct usb_function *func,
ncm->usb = usb;
ncm->bus = usb->port->hub->bus;
ncm->netdev = netdev;
usb_endpoint_init ( &ncm->intr.ep, usb, &ncm_intr_operations );
usb_endpoint_init ( &ncm->in.ep, usb, &ncm_in_operations );
usb_endpoint_init ( &ncm->out.ep, usb, &ncm_out_operations );
usb_endpoint_init ( &ncm->intr, usb, &ncm_intr_operations );
usb_endpoint_init ( &ncm->in, usb, &ncm_in_operations );
usb_endpoint_init ( &ncm->out, usb, &ncm_out_operations );
usb_refill_init ( &ncm->intr, 0, NCM_INTR_COUNT );
DBGC ( ncm, "NCM %p on %s\n", ncm, func->name );
/* Identify interfaces */
@ -843,7 +699,7 @@ static int ncm_probe ( struct usb_function *func,
}
/* Describe interrupt endpoint */
if ( ( rc = usb_endpoint_described ( &ncm->intr.ep, config, comms,
if ( ( rc = usb_endpoint_described ( &ncm->intr, config, comms,
USB_INTERRUPT, 0 ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not describe interrupt endpoint: "
"%s\n", ncm, strerror ( rc ) );
@ -851,7 +707,7 @@ static int ncm_probe ( struct usb_function *func,
}
/* Describe bulk IN endpoint */
if ( ( rc = usb_endpoint_described ( &ncm->in.ep, config, data,
if ( ( rc = usb_endpoint_described ( &ncm->in, config, data,
USB_BULK_IN, 0 ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not describe bulk IN endpoint: "
"%s\n", ncm, strerror ( rc ) );
@ -859,7 +715,7 @@ static int ncm_probe ( struct usb_function *func,
}
/* Describe bulk OUT endpoint */
if ( ( rc = usb_endpoint_described ( &ncm->out.ep, config, data,
if ( ( rc = usb_endpoint_described ( &ncm->out, config, data,
USB_BULK_OUT, 0 ) ) != 0 ) {
DBGC ( ncm, "NCM %p could not describe bulk OUT endpoint: "
"%s\n", ncm, strerror ( rc ) );
@ -894,12 +750,12 @@ static int ncm_probe ( struct usb_function *func,
DBGC2 ( ncm, "NCM %p maximum IN size is %zd bytes\n", ncm, ncm->mtu );
/* Calculate transmit padding */
ncm->out.padding = ( ( le16_to_cpu ( params.out.remainder ) -
ncm->padding = ( ( le16_to_cpu ( params.out.remainder ) -
sizeof ( struct ncm_ntb_header ) - ETH_HLEN ) &
( le16_to_cpu ( params.out.divisor ) - 1 ) );
DBGC2 ( ncm, "NCM %p using %zd-byte transmit padding\n",
ncm, ncm->out.padding );
assert ( ( ( sizeof ( struct ncm_ntb_header ) + ncm->out.padding +
ncm, ncm->padding );
assert ( ( ( sizeof ( struct ncm_ntb_header ) + ncm->padding +
ETH_HLEN ) % le16_to_cpu ( params.out.divisor ) ) ==
le16_to_cpu ( params.out.remainder ) );

36
src/drivers/net/ncm.h
View File

@ -139,26 +139,6 @@ struct ncm_ntb_header {
struct ncm_datagram_descriptor desc[2];
} __attribute__ (( packed ));
/** A CDC-NCM receive ring */
struct ncm_rx_ring {
/** USB endpoint */
struct usb_endpoint ep;
/** I/O buffer size */
size_t mtu;
/** Recycled buffer list */
struct list_head list;
};
/** A CDC-NCM transmit ring */
struct ncm_tx_ring {
/** USB endpoint */
struct usb_endpoint ep;
/** Transmitted packet sequence number */
uint16_t sequence;
/** Alignment padding required on transmitted packets */
size_t padding;
};
/** A CDC-NCM network device */
struct ncm_device {
/** USB device */
@ -175,13 +155,17 @@ struct ncm_device {
/** Maximum supported NTB input size */
size_t mtu;
/** Transmitted packet sequence number */
uint16_t sequence;
/** Alignment padding required on transmitted packets */
size_t padding;
/** Interrupt ring */
struct ncm_rx_ring intr;
/** Bulk IN ring */
struct ncm_rx_ring in;
/** Bulk OUT ring */
struct ncm_tx_ring out;
/** Interrupt endpoint */
struct usb_endpoint intr;
/** Bulk IN endpoint */
struct usb_endpoint in;
/** Bulk OUT endpoint */
struct usb_endpoint out;
};
/** Bulk IN ring minimum buffer count