This series adds the ability to support packaging multiple network
packets into a single 16k CDC-NCM NTB.
Patches 1 and 3 are fixes for the receive unwrap function which
previously was unable to handle an NTB with multiple NDP's and a fix
that switches from using skb_clone to creating a new packet to fix the
issue of the truesize being far to big and causing packets to be
dropped incorrectly.
Jim Baxter (3):
usb: gadget: NCM: RX function support multiple NDPs
usb: gadget: NCM: Add transmit multi-frame.
usb: gadget: NCM: Stop RX TCP Bursts getting dropped.
drivers/usb/gadget/f_ncm.c | 480 +++++++++++++++++++++++++++++-------------
drivers/usb/gadget/u_ether.c | 19 +-
drivers/usb/gadget/u_ether.h | 2 +
3 files changed, 347 insertions(+), 154 deletions(-)
--
1.7.9.5
This adds multi-frame support to the NCM NTB's for
the gadget driver. This allows multiple network
packets to be put inside a single USB NTB with a
maximum size of 16kB.
It has a time out of 300ms to ensure that smaller
number of packets still maintain a normal latency.
Also the .fp_index and .next_fp_index have been
changed to .ndp_index and .next_ndp_index to
match the latest CDC-NCM specification and
help with maintenance.
Results transmitting from gadget to host.
Before the change:
TCP_STREAM Throughput (10^6bits/sec): 22.72
UDP_STREAM Throughput (10^6bits/sec): 25.94
Latency:
netperf -H 192.168.1.101 -v2 -l 50 -t TCP_RR -- -r 16384,16384
Trans. RoundTrip Throughput
Rate Latency 10^6bits/s
per sec usec/Tran Outbound
100.83 9918.116 13.215
After the change:
TCP_STREAM Throughput (10^6bits/sec): 124.26
UDP_STREAM Throughput (10^6bits/sec): 227.48
Latency:
netperf -H 192.168.1.101 -v2 -l 50 -t TCP_RR -- -r 16384,16384
Trans. RoundTrip Throughput
Rate Latency 10^6bits/s
per sec usec/Tran Outbound
156.80 6377.730 20.552
Signed-off-by: Jim Baxter <[email protected]>
---
drivers/usb/gadget/f_ncm.c | 335 ++++++++++++++++++++++++++++++++----------
drivers/usb/gadget/u_ether.c | 19 ++-
drivers/usb/gadget/u_ether.h | 2 +
3 files changed, 269 insertions(+), 87 deletions(-)
diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c
index d0ebbac..5452fb6 100644
--- a/drivers/usb/gadget/f_ncm.c
+++ b/drivers/usb/gadget/f_ncm.c
@@ -68,6 +68,18 @@ struct f_ncm {
* callback and ethernet open/close
*/
spinlock_t lock;
+
+ struct net_device *netdev;
+
+ /* For multi-frame NDP TX */
+ struct sk_buff *skb_tx_data;
+ struct sk_buff *skb_tx_ndp;
+ u16 ndp_dgram_count;
+ bool timer_force_tx;
+ struct tasklet_struct tx_tasklet;
+ struct hrtimer task_timer;
+
+ bool timer_stopping;
};
static inline struct f_ncm *func_to_ncm(struct usb_function *f)
@@ -92,15 +104,20 @@ static inline unsigned ncm_bitrate(struct usb_gadget *g)
* If the host can group frames, allow it to do that, 16K is selected,
* because it's used by default by the current linux host driver
*/
-#define NTB_DEFAULT_IN_SIZE USB_CDC_NCM_NTB_MIN_IN_SIZE
+#define NTB_DEFAULT_IN_SIZE 16384
#define NTB_OUT_SIZE 16384
-/*
- * skbs of size less than that will not be aligned
- * to NCM's dwNtbInMaxSize to save bus bandwidth
+/* Allocation for storing the NDP, 32 should suffice for a
+ * 16k packet. This allows a maximum of 32 * 507 Byte packets to
+ * be transmitted in a single 16kB skb, though when sending full size
+ * packets this limit will be plenty.
+ * Smaller packets are not likely to be trying to maximize the
+ * throughput and will be mstly sending smaller infrequent frames.
*/
+#define TX_MAX_NUM_DPE 32
-#define MAX_TX_NONFIXED (512 * 3)
+/* Delay for the transmit to wait before sending an unfilled NTB frame. */
+#define TX_TIMEOUT_NSECS 300000
#define FORMATS_SUPPORTED (USB_CDC_NCM_NTB16_SUPPORTED | \
USB_CDC_NCM_NTB32_SUPPORTED)
@@ -355,14 +372,15 @@ struct ndp_parser_opts {
u32 ndp_sign;
unsigned nth_size;
unsigned ndp_size;
+ unsigned dpe_size;
unsigned ndplen_align;
/* sizes in u16 units */
unsigned dgram_item_len; /* index or length */
unsigned block_length;
- unsigned fp_index;
+ unsigned ndp_index;
unsigned reserved1;
unsigned reserved2;
- unsigned next_fp_index;
+ unsigned next_ndp_index;
};
#define INIT_NDP16_OPTS { \
@@ -370,13 +388,14 @@ struct ndp_parser_opts {
.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN, \
.nth_size = sizeof(struct usb_cdc_ncm_nth16), \
.ndp_size = sizeof(struct usb_cdc_ncm_ndp16), \
+ .dpe_size = sizeof(struct usb_cdc_ncm_dpe16), \
.ndplen_align = 4, \
.dgram_item_len = 1, \
.block_length = 1, \
- .fp_index = 1, \
+ .ndp_index = 1, \
.reserved1 = 0, \
.reserved2 = 0, \
- .next_fp_index = 1, \
+ .next_ndp_index = 1, \
}
@@ -385,13 +404,14 @@ struct ndp_parser_opts {
.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN, \
.nth_size = sizeof(struct usb_cdc_ncm_nth32), \
.ndp_size = sizeof(struct usb_cdc_ncm_ndp32), \
+ .dpe_size = sizeof(struct usb_cdc_ncm_dpe32), \
.ndplen_align = 8, \
.dgram_item_len = 2, \
.block_length = 2, \
- .fp_index = 2, \
+ .ndp_index = 2, \
.reserved1 = 1, \
.reserved2 = 2, \
- .next_fp_index = 2, \
+ .next_ndp_index = 2, \
}
static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
@@ -803,6 +823,8 @@ static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
if (ncm->port.in_ep->driver_data) {
DBG(cdev, "reset ncm\n");
+ ncm->timer_stopping = true;
+ ncm->netdev = NULL;
gether_disconnect(&ncm->port);
ncm_reset_values(ncm);
}
@@ -839,6 +861,8 @@ static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
net = gether_connect(&ncm->port);
if (IS_ERR(net))
return PTR_ERR(net);
+ ncm->netdev = net;
+ ncm->timer_stopping = false;
}
spin_lock(&ncm->lock);
@@ -865,95 +889,232 @@ static int ncm_get_alt(struct usb_function *f, unsigned intf)
return ncm->port.in_ep->driver_data ? 1 : 0;
}
+static struct sk_buff *package_for_tx(struct f_ncm *ncm)
+{
+ __le16 *ntb_iter;
+ struct sk_buff *skb2 = NULL;
+ unsigned ndp_pad;
+ unsigned ndp_index;
+ unsigned new_len;
+
+ const struct ndp_parser_opts *opts = ncm->parser_opts;
+ const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
+ const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
+
+ /* Stop the timer */
+ hrtimer_try_to_cancel(&ncm->task_timer);
+
+ ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
+ ncm->skb_tx_data->len;
+ ndp_index = ncm->skb_tx_data->len + ndp_pad;
+ new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
+
+ /* Set the final BlockLength and wNdpIndex */
+ ntb_iter = (void *) ncm->skb_tx_data->data;
+ /* Increment pointer to BlockLength */
+ ntb_iter += 2 + 1 + 1;
+ put_ncm(&ntb_iter, opts->block_length, new_len);
+ put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
+
+ /* Set the final NDP wLength */
+ new_len = opts->ndp_size +
+ (ncm->ndp_dgram_count * dgram_idx_len);
+ ncm->ndp_dgram_count = 0;
+ /* Increment from start to wLength */
+ ntb_iter = (void *) ncm->skb_tx_ndp->data;
+ ntb_iter += 2;
+ put_unaligned_le16(new_len, ntb_iter);
+
+ /* Merge the skbs */
+ swap(skb2, ncm->skb_tx_data);
+ if (ncm->skb_tx_data) {
+ dev_kfree_skb_any(ncm->skb_tx_data);
+ ncm->skb_tx_data = NULL;
+ }
+
+ /* Insert NDP alignment. */
+ ntb_iter = (void *) skb_put(skb2, ndp_pad);
+ memset(ntb_iter, 0, ndp_pad);
+
+ /* Copy NTB across. */
+ ntb_iter = (void *) skb_put(skb2, ncm->skb_tx_ndp->len);
+ memcpy(ntb_iter, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
+ dev_kfree_skb_any(ncm->skb_tx_ndp);
+ ncm->skb_tx_ndp = NULL;
+
+ /* Insert zero'd datagram. */
+ ntb_iter = (void *) skb_put(skb2, dgram_idx_len);
+ memset(ntb_iter, 0, dgram_idx_len);
+
+ return skb2;
+}
+
static struct sk_buff *ncm_wrap_ntb(struct gether *port,
struct sk_buff *skb)
{
struct f_ncm *ncm = func_to_ncm(&port->func);
- struct sk_buff *skb2;
+ struct sk_buff *skb2 = NULL;
int ncb_len = 0;
- __le16 *tmp;
- int div;
- int rem;
- int pad;
- int ndp_align;
- int ndp_pad;
+ __le16 *ntb_data;
+ __le16 *ntb_ndp;
+ int dgram_pad;
+
unsigned max_size = ncm->port.fixed_in_len;
const struct ndp_parser_opts *opts = ncm->parser_opts;
- unsigned crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
-
- div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
- rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
- ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
-
- ncb_len += opts->nth_size;
- ndp_pad = ALIGN(ncb_len, ndp_align) - ncb_len;
- ncb_len += ndp_pad;
- ncb_len += opts->ndp_size;
- ncb_len += 2 * 2 * opts->dgram_item_len; /* Datagram entry */
- ncb_len += 2 * 2 * opts->dgram_item_len; /* Zero datagram entry */
- pad = ALIGN(ncb_len, div) + rem - ncb_len;
- ncb_len += pad;
+ const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
+ const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
+ const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
+ const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
- if (ncb_len + skb->len + crc_len > max_size) {
- dev_kfree_skb_any(skb);
+ if (!skb && !ncm->skb_tx_data)
return NULL;
- }
- skb2 = skb_copy_expand(skb, ncb_len,
- max_size - skb->len - ncb_len - crc_len,
- GFP_ATOMIC);
- dev_kfree_skb_any(skb);
- if (!skb2)
- return NULL;
+ if (skb) {
+ /* Add the CRC if required up front */
+ if (ncm->is_crc) {
+ uint32_t crc;
+ __le16 *crc_pos;
+
+ crc = ~crc32_le(~0,
+ skb->data,
+ skb->len);
+ crc_pos = (void *) skb_put(skb, sizeof(uint32_t));
+ put_unaligned_le32(crc, crc_pos);
+ }
- skb = skb2;
+ /* If the new skb is too big for the current NCM NTB then
+ * set the current stored skb to be sent now and clear it
+ * ready for new data.
+ * NOTE: Assume maximum align for speed of calculation.
+ */
+ if (ncm->skb_tx_data
+ && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
+ || (ncm->skb_tx_data->len +
+ div + rem + skb->len +
+ ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
+ > max_size)) {
+ skb2 = package_for_tx(ncm);
+ if (!skb2)
+ goto err;
+ }
- tmp = (void *) skb_push(skb, ncb_len);
- memset(tmp, 0, ncb_len);
+ if (!ncm->skb_tx_data) {
+ ncb_len = opts->nth_size;
+ dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
+ ncb_len += dgram_pad;
- put_unaligned_le32(opts->nth_sign, tmp); /* dwSignature */
- tmp += 2;
- /* wHeaderLength */
- put_unaligned_le16(opts->nth_size, tmp++);
- tmp++; /* skip wSequence */
- put_ncm(&tmp, opts->block_length, skb->len); /* (d)wBlockLength */
- /* (d)wFpIndex */
- /* the first pointer is right after the NTH + align */
- put_ncm(&tmp, opts->fp_index, opts->nth_size + ndp_pad);
+ /* Create a new skb for the NTH and datagrams. */
+ ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
+ if (!ncm->skb_tx_data)
+ goto err;
- tmp = (void *)tmp + ndp_pad;
+ ntb_data = (void *) skb_put(ncm->skb_tx_data, ncb_len);
+ memset(ntb_data, 0, ncb_len);
+ /* dwSignature */
+ put_unaligned_le32(opts->nth_sign, ntb_data);
+ ntb_data += 2;
+ /* wHeaderLength */
+ put_unaligned_le16(opts->nth_size, ntb_data++);
+
+ /* Allocate an skb for storing the NDP,
+ * TX_MAX_NUM_DPE should easily suffice for a
+ * 16k packet.
+ */
+ ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
+ + opts->dpe_size
+ * TX_MAX_NUM_DPE),
+ GFP_ATOMIC);
+ if (!ncm->skb_tx_ndp)
+ goto err;
+ ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp,
+ opts->ndp_size);
+ memset(ntb_ndp, 0, ncb_len);
+ /* dwSignature */
+ put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
+ ntb_ndp += 2;
- /* NDP */
- put_unaligned_le32(ncm->ndp_sign, tmp); /* dwSignature */
- tmp += 2;
- /* wLength */
- put_unaligned_le16(ncb_len - opts->nth_size - pad, tmp++);
+ /* There is always a zeroed entry */
+ ncm->ndp_dgram_count = 1;
- tmp += opts->reserved1;
- tmp += opts->next_fp_index; /* skip reserved (d)wNextFpIndex */
- tmp += opts->reserved2;
+ /* Note: we skip opts->next_ndp_index */
+ }
- if (ncm->is_crc) {
- uint32_t crc;
+ /* Delay the timer. */
+ hrtimer_start(&ncm->task_timer,
+ ktime_set(0, TX_TIMEOUT_NSECS),
+ HRTIMER_MODE_REL);
+
+ /* Add the datagram position entries */
+ ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp, dgram_idx_len);
+ memset(ntb_ndp, 0, dgram_idx_len);
+
+ ncb_len = ncm->skb_tx_data->len;
+ dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
+ ncb_len += dgram_pad;
+
+ /* (d)wDatagramIndex */
+ put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
+ /* (d)wDatagramLength */
+ put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
+ ncm->ndp_dgram_count++;
+
+ /* Add the new data to the skb */
+ ntb_data = (void *) skb_put(ncm->skb_tx_data, dgram_pad);
+ memset(ntb_data, 0, dgram_pad);
+ ntb_data = (void *) skb_put(ncm->skb_tx_data, skb->len);
+ memcpy(ntb_data, skb->data, skb->len);
+ dev_kfree_skb_any(skb);
+ skb = NULL;
- crc = ~crc32_le(~0,
- skb->data + ncb_len,
- skb->len - ncb_len);
- put_unaligned_le32(crc, skb->data + skb->len);
- skb_put(skb, crc_len);
+ } else if (ncm->skb_tx_data && ncm->timer_force_tx) {
+ /* If the tx was requested because of a timeout then send */
+ skb2 = package_for_tx(ncm);
+ if (!skb2)
+ goto err;
}
- /* (d)wDatagramIndex[0] */
- put_ncm(&tmp, opts->dgram_item_len, ncb_len);
- /* (d)wDatagramLength[0] */
- put_ncm(&tmp, opts->dgram_item_len, skb->len - ncb_len);
- /* (d)wDatagramIndex[1] and (d)wDatagramLength[1] already zeroed */
+ return skb2;
+
+err:
+ ncm->netdev->stats.tx_dropped++;
+
+ if (skb)
+ dev_kfree_skb_any(skb);
+ if (ncm->skb_tx_data)
+ dev_kfree_skb_any(ncm->skb_tx_data);
+ if (ncm->skb_tx_ndp)
+ dev_kfree_skb_any(ncm->skb_tx_ndp);
+
+ return NULL;
+}
+
+/*
+ * This transmits the NTB if there are frames waiting.
+ */
+static void ncm_tx_tasklet(unsigned long data)
+{
+ struct f_ncm *ncm = (void *)data;
- if (skb->len > MAX_TX_NONFIXED)
- memset(skb_put(skb, max_size - skb->len),
- 0, max_size - skb->len);
+ if (ncm->timer_stopping)
+ return;
+
+ /* Only send if data is available. */
+ if (ncm->skb_tx_data) {
+ ncm->timer_force_tx = true;
+ ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
+ ncm->timer_force_tx = false;
+ }
+}
- return skb;
+/*
+ * The transmit should only be run if no skb data has been sent
+ * for a certain duration.
+ */
+static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
+{
+ struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
+ tasklet_schedule(&ncm->tx_tasklet);
+ return HRTIMER_NORESTART;
}
static int ncm_unwrap_ntb(struct gether *port,
@@ -996,7 +1157,7 @@ static int ncm_unwrap_ntb(struct gether *port,
goto err;
}
- ndp_index = get_ncm(&tmp, opts->fp_index);
+ ndp_index = get_ncm(&tmp, opts->ndp_index);
/* Run through all the NDP's in the NTB */
do {
@@ -1033,7 +1194,7 @@ static int ncm_unwrap_ntb(struct gether *port,
}
tmp += opts->reserved1;
/* Check for another NDP (d)wNextNdpIndex */
- ndp_index = get_ncm(&tmp, opts->next_fp_index);
+ ndp_index = get_ncm(&tmp, opts->next_ndp_index);
tmp += opts->reserved2;
ndp_len -= opts->ndp_size;
@@ -1107,8 +1268,11 @@ static void ncm_disable(struct usb_function *f)
DBG(cdev, "ncm deactivated\n");
- if (ncm->port.in_ep->driver_data)
+ if (ncm->port.in_ep->driver_data) {
+ ncm->timer_stopping = true;
+ ncm->netdev = NULL;
gether_disconnect(&ncm->port);
+ }
if (ncm->notify->driver_data) {
usb_ep_disable(ncm->notify);
@@ -1277,6 +1441,10 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
ncm->port.open = ncm_open;
ncm->port.close = ncm_close;
+ tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm);
+ hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ ncm->task_timer.function = ncm_tx_timeout;
+
DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
ncm->port.in_ep->name, ncm->port.out_ep->name,
@@ -1390,6 +1558,10 @@ static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
DBG(c->cdev, "ncm unbind\n");
+ hrtimer_cancel(&ncm->task_timer);
+ tasklet_kill(&ncm->tx_tasklet);
+
+ ncm_string_defs[0].id = 0;
usb_free_all_descriptors(f);
kfree(ncm->notify_req->buf);
@@ -1426,6 +1598,7 @@ static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
ncm->port.ioport = netdev_priv(opts->net);
mutex_unlock(&opts->lock);
ncm->port.is_fixed = true;
+ ncm->port.supports_multi_frame = true;
ncm->port.func.name = "cdc_network";
/* descriptors are per-instance copies */
diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c
index 97b0277..d50adda 100644
--- a/drivers/usb/gadget/u_ether.c
+++ b/drivers/usb/gadget/u_ether.c
@@ -483,7 +483,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
- int length = skb->len;
+ int length = 0;
int retval;
struct usb_request *req = NULL;
unsigned long flags;
@@ -500,13 +500,13 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
}
spin_unlock_irqrestore(&dev->lock, flags);
- if (!in) {
+ if (skb && !in) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/* apply outgoing CDC or RNDIS filters */
- if (!is_promisc(cdc_filter)) {
+ if (skb && !is_promisc(cdc_filter)) {
u8 *dest = skb->data;
if (is_multicast_ether_addr(dest)) {
@@ -557,11 +557,17 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
if (dev->port_usb)
skb = dev->wrap(dev->port_usb, skb);
spin_unlock_irqrestore(&dev->lock, flags);
- if (!skb)
+ if (!skb) {
+ /* Multi frame CDC protocols may store the frame for
+ * later which is not a dropped frame.
+ */
+ if (dev->port_usb->supports_multi_frame)
+ goto multiframe;
goto drop;
-
- length = skb->len;
+ }
}
+
+ length = skb->len;
req->buf = skb->data;
req->context = skb;
req->complete = tx_complete;
@@ -604,6 +610,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
dev_kfree_skb_any(skb);
drop:
dev->net->stats.tx_dropped++;
+multiframe:
spin_lock_irqsave(&dev->req_lock, flags);
if (list_empty(&dev->tx_reqs))
netif_start_queue(net);
diff --git a/drivers/usb/gadget/u_ether.h b/drivers/usb/gadget/u_ether.h
index 0f0290a..334b389 100644
--- a/drivers/usb/gadget/u_ether.h
+++ b/drivers/usb/gadget/u_ether.h
@@ -18,6 +18,7 @@
#include <linux/if_ether.h>
#include <linux/usb/composite.h>
#include <linux/usb/cdc.h>
+#include <linux/netdevice.h>
#include "gadget_chips.h"
@@ -74,6 +75,7 @@ struct gether {
bool is_fixed;
u32 fixed_out_len;
u32 fixed_in_len;
+ bool supports_multi_frame;
struct sk_buff *(*wrap)(struct gether *port,
struct sk_buff *skb);
int (*unwrap)(struct gether *port,
--
1.7.9.5
This fixes a problem with dropped packets over 16k CDC-NCM
when the connection is being heavily used.
The issue was that the extracted frames cloned from the
received frame were consuming more memory than necessary
resulting in the truesize being ~32KB instead of ~2KB, this
meant there was a high chance of reaching the sk_rcvbuf
limit.
Signed-off-by: Jim Baxter <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
---
Updated the commit message to accurately describe the issue.
drivers/usb/gadget/f_ncm.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c
index 5452fb6..bcdc882 100644
--- a/drivers/usb/gadget/f_ncm.c
+++ b/drivers/usb/gadget/f_ncm.c
@@ -1229,16 +1229,17 @@ static int ncm_unwrap_ntb(struct gether *port,
index2 = get_ncm(&tmp, opts->dgram_item_len);
dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
- skb2 = skb_clone(skb, GFP_ATOMIC);
+ /*
+ * Copy the data into a new skb.
+ * This ensures the truesize is correct
+ */
+ skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
+ dg_len - crc_len);
if (skb2 == NULL)
goto err;
+ memcpy(skb_put(skb2, dg_len - crc_len),
+ skb->data + index, dg_len - crc_len);
- if (!skb_pull(skb2, index)) {
- ret = -EOVERFLOW;
- goto err;
- }
-
- skb_trim(skb2, dg_len - crc_len);
skb_queue_tail(list, skb2);
ndp_len -= 2 * (opts->dgram_item_len * 2);
--
1.7.9.5
The NDP was ignoring the wNextNdpIndex in the NDP which
means that NTBs containing multiple NDPs would have missed
frames.
Signed-off-by: Jim Baxter <[email protected]>
---
This patch originally came about because I read the CDC-NCM specification
Figures 3-1, 3-2 and table 3-4 which specifies 32bit NDPs as a link.
It has since been noted that table 3-3 states it is reserved so there is
an inconsistancy in the specfification which this patch covers either
version of.
drivers/usb/gadget/f_ncm.c | 146 +++++++++++++++++++++++---------------------
1 file changed, 78 insertions(+), 68 deletions(-)
diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c
index a9499fd..d0ebbac 100644
--- a/drivers/usb/gadget/f_ncm.c
+++ b/drivers/usb/gadget/f_ncm.c
@@ -963,6 +963,7 @@ static int ncm_unwrap_ntb(struct gether *port,
struct f_ncm *ncm = func_to_ncm(&port->func);
__le16 *tmp = (void *) skb->data;
unsigned index, index2;
+ int ndp_index;
unsigned dg_len, dg_len2;
unsigned ndp_len;
struct sk_buff *skb2;
@@ -995,91 +996,100 @@ static int ncm_unwrap_ntb(struct gether *port,
goto err;
}
- index = get_ncm(&tmp, opts->fp_index);
- /* NCM 3.2 */
- if (((index % 4) != 0) && (index < opts->nth_size)) {
- INFO(port->func.config->cdev, "Bad index: %x\n",
- index);
- goto err;
- }
-
- /* walk through NDP */
- tmp = ((void *)skb->data) + index;
- if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
- INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
- goto err;
- }
- tmp += 2;
-
- ndp_len = get_unaligned_le16(tmp++);
- /*
- * NCM 3.3.1
- * entry is 2 items
- * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
- * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
- */
- if ((ndp_len < opts->ndp_size + 2 * 2 * (opts->dgram_item_len * 2))
- || (ndp_len % opts->ndplen_align != 0)) {
- INFO(port->func.config->cdev, "Bad NDP length: %x\n", ndp_len);
- goto err;
- }
- tmp += opts->reserved1;
- tmp += opts->next_fp_index; /* skip reserved (d)wNextFpIndex */
- tmp += opts->reserved2;
-
- ndp_len -= opts->ndp_size;
- index2 = get_ncm(&tmp, opts->dgram_item_len);
- dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
- dgram_counter = 0;
+ ndp_index = get_ncm(&tmp, opts->fp_index);
+ /* Run through all the NDP's in the NTB */
do {
- index = index2;
- dg_len = dg_len2;
- if (dg_len < 14 + crc_len) { /* ethernet header + crc */
- INFO(port->func.config->cdev, "Bad dgram length: %x\n",
- dg_len);
+ /* NCM 3.2 */
+ if (((ndp_index % 4) != 0) &&
+ (ndp_index < opts->nth_size)) {
+ INFO(port->func.config->cdev, "Bad index: %#X\n",
+ ndp_index);
goto err;
}
- if (ncm->is_crc) {
- uint32_t crc, crc2;
-
- crc = get_unaligned_le32(skb->data +
- index + dg_len - crc_len);
- crc2 = ~crc32_le(~0,
- skb->data + index,
- dg_len - crc_len);
- if (crc != crc2) {
- INFO(port->func.config->cdev, "Bad CRC\n");
- goto err;
- }
+
+ /* walk through NDP */
+ tmp = (void *)(skb->data + ndp_index);
+ if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
+ INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
+ goto err;
}
+ tmp += 2;
+ ndp_len = get_unaligned_le16(tmp++);
+ /*
+ * NCM 3.3.1
+ * entry is 2 items
+ * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
+ * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
+ * Each entry is a dgram index and a dgram length.
+ */
+ if ((ndp_len < opts->ndp_size
+ + 2 * 2 * (opts->dgram_item_len * 2))
+ || (ndp_len % opts->ndplen_align != 0)) {
+ INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
+ ndp_len);
+ goto err;
+ }
+ tmp += opts->reserved1;
+ /* Check for another NDP (d)wNextNdpIndex */
+ ndp_index = get_ncm(&tmp, opts->next_fp_index);
+ tmp += opts->reserved2;
+
+ ndp_len -= opts->ndp_size;
index2 = get_ncm(&tmp, opts->dgram_item_len);
dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
+ dgram_counter = 0;
+
+ do {
+ index = index2;
+ dg_len = dg_len2;
+ if (dg_len < 14 + crc_len) { /* ethernet hdr + crc */
+ INFO(port->func.config->cdev,
+ "Bad dgram length: %#X\n", dg_len);
+ goto err;
+ }
+ if (ncm->is_crc) {
+ uint32_t crc, crc2;
+
+ crc = get_unaligned_le32(skb->data +
+ index + dg_len -
+ crc_len);
+ crc2 = ~crc32_le(~0,
+ skb->data + index,
+ dg_len - crc_len);
+ if (crc != crc2) {
+ INFO(port->func.config->cdev,
+ "Bad CRC\n");
+ goto err;
+ }
+ }
+
+ index2 = get_ncm(&tmp, opts->dgram_item_len);
+ dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
- if (index2 == 0 || dg_len2 == 0) {
- skb2 = skb;
- } else {
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2 == NULL)
goto err;
- }
- if (!skb_pull(skb2, index)) {
- ret = -EOVERFLOW;
- goto err;
- }
+ if (!skb_pull(skb2, index)) {
+ ret = -EOVERFLOW;
+ goto err;
+ }
- skb_trim(skb2, dg_len - crc_len);
- skb_queue_tail(list, skb2);
+ skb_trim(skb2, dg_len - crc_len);
+ skb_queue_tail(list, skb2);
- ndp_len -= 2 * (opts->dgram_item_len * 2);
+ ndp_len -= 2 * (opts->dgram_item_len * 2);
- dgram_counter++;
+ dgram_counter++;
- if (index2 == 0 || dg_len2 == 0)
- break;
- } while (ndp_len > 2 * (opts->dgram_item_len * 2)); /* zero entry */
+ if (index2 == 0 || dg_len2 == 0)
+ break;
+ } while (ndp_len > 2 * (opts->dgram_item_len * 2));
+ } while (ndp_index);
+
+ dev_kfree_skb_any(skb);
VDBG(port->func.config->cdev,
"Parsed NTB with %d frames\n", dgram_counter);
--
1.7.9.5