Files
android_kernel_samsung_sm86…/dp/wifi3.0/dp_rx_err.c
Karunakar Dasineni e8380bbece qcacmn: REO descriptor changes
Disable CHK_2K_MODE and OOR_MODE in REO descriptor. Also set RTY bit for non-BA TID queues as temporary WAR for duplicate detection issue.

Change-Id: Ifa51c20ffbfe31c807d4e7f99014cb76f411e066
2017-01-19 12:46:37 -08:00

687 lines
19 KiB
C

/*
* Copyright (c) 2016-2017 The Linux Foundation. All rights reserved.
*
* Permission to use, copy, modify, and/or distribute this software for
* any purpose with or without fee is hereby granted, provided that the
* above copyright notice and this permission notice appear in all
* copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
* AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#include "dp_types.h"
#include "dp_rx.h"
#include "dp_peer.h"
#include "dp_internal.h"
#include "hal_api.h"
#include "qdf_trace.h"
#include "qdf_nbuf.h"
#ifdef CONFIG_MCL
#include <cds_ieee80211_common.h>
#else
#include <ieee80211.h>
#endif
/**
* dp_rx_cookie_2_link_desc_va() - Converts cookie to a virtual address of
* the MSDU Link Descriptor
* @soc: core txrx main context
* @cookie: cookie used to lookup virtual address of link descriptor
* Normally this is just an index into a per SOC array.
*
* This is the VA of the link descriptor, that HAL layer later uses to
* retrieve the list of MSDU's for a given .
*
* Return: void *: Virtual Address of the Rx descriptor
*/
static inline
void *dp_rx_cookie_2_link_desc_va(struct dp_soc *soc,
struct hal_buf_info *buf_info)
{
void *link_desc_va;
/* TODO */
/* Add sanity for cookie */
link_desc_va = soc->link_desc_banks[buf_info->sw_cookie].base_vaddr +
(buf_info->paddr -
soc->link_desc_banks[buf_info->sw_cookie].base_paddr);
return link_desc_va;
}
/**
* dp_rx_frag_handle() - Handles fragmented Rx frames
*
* @soc: core txrx main context
* @ring_desc: opaque pointer to the REO error ring descriptor
* @mpdu_desc_info: MPDU descriptor information from ring descriptor
* @head: head of the local descriptor free-list
* @tail: tail of the local descriptor free-list
* @quota: No. of units (packets) that can be serviced in one shot.
*
* This function implements RX 802.11 fragmentation handling
* The handling is mostly same as legacy fragmentation handling.
* If required, this function can re-inject the frames back to
* REO ring (with proper setting to by-pass fragmentation check
* but use duplicate detection / re-ordering and routing these frames
* to a different core.
*
* Return: uint32_t: No. of elements processed
*/
static uint32_t
dp_rx_frag_handle(struct dp_soc *soc, void *ring_desc,
struct hal_rx_mpdu_desc_info *mpdu_desc_info,
union dp_rx_desc_list_elem_t **head,
union dp_rx_desc_list_elem_t **tail,
uint32_t quota)
{
uint32_t rx_bufs_used = 0;
return rx_bufs_used;
}
/**
* dp_rx_msdus_drop() - Drops all MSDU's per MPDU
*
* @soc: core txrx main context
* @ring_desc: opaque pointer to the REO error ring descriptor
* @mpdu_desc_info: MPDU descriptor information from ring descriptor
* @head: head of the local descriptor free-list
* @tail: tail of the local descriptor free-list
* @quota: No. of units (packets) that can be serviced in one shot.
*
* This function is used to drop all MSDU in an MPDU
*
* Return: uint32_t: No. of elements processed
*/
static uint32_t
dp_rx_msdus_drop(struct dp_soc *soc, void *ring_desc,
struct hal_rx_mpdu_desc_info *mpdu_desc_info,
union dp_rx_desc_list_elem_t **head,
union dp_rx_desc_list_elem_t **tail,
uint32_t quota)
{
uint8_t num_msdus;
uint32_t rx_bufs_used = 0;
void *link_desc_va;
struct hal_buf_info buf_info;
struct hal_rx_msdu_list msdu_list; /* MSDU's per MPDU */
int i;
hal_rx_reo_buf_paddr_get(ring_desc, &buf_info);
link_desc_va = dp_rx_cookie_2_link_desc_va(soc, &buf_info);
qdf_assert(rx_msdu_link_desc);
/* No UNMAP required -- this is "malloc_consistent" memory */
hal_rx_msdu_list_get(link_desc_va, &msdu_list, &num_msdus);
for (i = 0; (i < HAL_RX_NUM_MSDU_DESC) && quota--; i++) {
struct dp_rx_desc *rx_desc =
dp_rx_cookie_2_va(soc, msdu_list.sw_cookie[i]);
qdf_assert(rx_desc);
rx_bufs_used++;
/* Just free the buffers */
qdf_nbuf_free(rx_desc->nbuf);
dp_rx_add_to_free_desc_list(head, tail, rx_desc);
}
return rx_bufs_used;
}
/**
* dp_rx_pn_error_handle() - Handles PN check errors
*
* @soc: core txrx main context
* @ring_desc: opaque pointer to the REO error ring descriptor
* @mpdu_desc_info: MPDU descriptor information from ring descriptor
* @head: head of the local descriptor free-list
* @tail: tail of the local descriptor free-list
* @quota: No. of units (packets) that can be serviced in one shot.
*
* This function implements PN error handling
* If the peer is configured to ignore the PN check errors
* or if DP feels, that this frame is still OK, the frame can be
* re-injected back to REO to use some of the other features
* of REO e.g. duplicate detection/routing to other cores
*
* Return: uint32_t: No. of elements processed
*/
static uint32_t
dp_rx_pn_error_handle(struct dp_soc *soc, void *ring_desc,
struct hal_rx_mpdu_desc_info *mpdu_desc_info,
union dp_rx_desc_list_elem_t **head,
union dp_rx_desc_list_elem_t **tail,
uint32_t quota)
{
uint16_t peer_id;
uint32_t rx_bufs_used = 0;
struct dp_peer *peer;
bool peer_pn_policy = false;
peer_id = DP_PEER_METADATA_PEER_ID_GET(
mpdu_desc_info->peer_meta_data);
peer = dp_peer_find_by_id(soc, peer_id);
if (qdf_likely(peer)) {
/*
* TODO: Check for peer specific policies & set peer_pn_policy
*/
}
/* No peer PN policy -- definitely drop */
if (!peer_pn_policy)
rx_bufs_used = dp_rx_msdus_drop(soc, ring_desc,
mpdu_desc_info,
head, tail, quota);
return rx_bufs_used;
}
/**
* dp_rx_2k_jump_handle() - Handles Sequence Number Jump by 2K
*
* @soc: core txrx main context
* @ring_desc: opaque pointer to the REO error ring descriptor
* @mpdu_desc_info: MPDU descriptor information from ring descriptor
* @head: head of the local descriptor free-list
* @tail: tail of the local descriptor free-list
* @quota: No. of units (packets) that can be serviced in one shot.
*
* This function implements the error handling when sequence number
* of the MPDU jumps suddenly by 2K.Today there are 2 cases that
* need to be handled:
* A) CSN (Current Sequence Number) = Last Valid SN (LSN) + 2K
* B) CSN = LSN + 2K, but falls within a "BA sized window" of the SSN
* For case A) the protocol stack is invoked to generate DELBA/DEAUTH frame
* For case B), the frame is normally dropped, no more action is taken
*
* Return: uint32_t: No. of elements processed
*/
static uint32_t
dp_rx_2k_jump_handle(struct dp_soc *soc, void *ring_desc,
struct hal_rx_mpdu_desc_info *mpdu_desc_info,
union dp_rx_desc_list_elem_t **head,
union dp_rx_desc_list_elem_t **tail,
uint32_t quota)
{
return dp_rx_msdus_drop(soc, ring_desc, mpdu_desc_info,
head, tail, quota);
}
/**
* dp_rx_null_q_desc_handle() - Function to handle NULL Queue
* descriptor violation on either a
* REO or WBM ring
*
* @soc: core DP main context
* @ring_desc: opaque pointer to the REO error ring descriptor
* @head: pointer to head of rx descriptors to be added to free list
* @tail: pointer to tail of rx descriptors to be added to free list
* quota: upper limit of descriptors that can be reaped
*
* This function handles NULL queue descriptor violations arising out
* a missing REO queue for a given peer or a given TID. This typically
* may happen if a packet is received on a QOS enabled TID before the
* ADDBA negotiation for that TID, when the TID queue is setup. Or
* it may also happen for MC/BC frames if they are not routed to the
* non-QOS TID queue, in the absence of any other default TID queue.
* This error can show up both in a REO destination or WBM release ring.
*
* Return: uint32_t: No. of Rx buffers reaped
*/
static uint32_t
dp_rx_null_q_desc_handle(struct dp_soc *soc, void *ring_desc,
union dp_rx_desc_list_elem_t **head,
union dp_rx_desc_list_elem_t **tail,
uint32_t quota)
{
uint32_t rx_buf_cookie;
struct dp_rx_desc *rx_desc;
uint32_t rx_bufs_used = 0;
uint32_t pkt_len, l2_hdr_offset;
uint16_t msdu_len;
qdf_nbuf_t nbuf;
struct dp_pdev *pdev0;
struct dp_vdev *vdev0;
uint32_t tid = 0;
uint16_t peer_id;
struct dp_peer *peer = NULL;
rx_buf_cookie = HAL_RX_WBM_BUF_COOKIE_GET(ring_desc);
rx_desc = dp_rx_cookie_2_va(soc, rx_buf_cookie);
qdf_assert(rx_desc);
rx_bufs_used++;
nbuf = rx_desc->nbuf;
qdf_nbuf_unmap_single(soc->osdev, nbuf,
QDF_DMA_BIDIRECTIONAL);
rx_desc->rx_buf_start = qdf_nbuf_data(nbuf);
l2_hdr_offset =
hal_rx_msdu_end_l3_hdr_padding_get(rx_desc->rx_buf_start);
msdu_len = hal_rx_msdu_start_msdu_len_get(rx_desc->rx_buf_start);
pkt_len = msdu_len + l2_hdr_offset + RX_PKT_TLVS_LEN;
/* Set length in nbuf */
qdf_nbuf_set_pktlen(nbuf, pkt_len);
/*
* Check if DMA completed -- msdu_done is the last bit
* to be written
*/
if (!hal_rx_attn_msdu_done_get(rx_desc->rx_buf_start)) {
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("nbuf->data 0x%p"), rx_desc->rx_buf_start);
qdf_assert(0);
}
/*
* Advance the packet start pointer by total size of
* pre-header TLV's
*/
qdf_nbuf_pull_head(nbuf, RX_PKT_TLVS_LEN);
if (l2_hdr_offset)
qdf_nbuf_pull_head(nbuf, l2_hdr_offset);
if (hal_rx_mpdu_start_mpdu_qos_control_valid_get(
rx_desc->rx_buf_start)) {
/* TODO: Assuming that qos_control_valid also indicates
* unicast. Should we check this?
*/
tid = hal_rx_mpdu_start_tid_get(rx_desc->rx_buf_start);
peer_id = hal_rx_mpdu_start_sw_peer_id_get(
rx_desc->rx_buf_start);
peer = dp_peer_find_by_id(soc, peer_id);
if (peer &&
peer->rx_tid[tid].hw_qdesc_vaddr_unaligned == NULL) {
/* IEEE80211_SEQ_MAX indicates invalid start_seq */
dp_rx_tid_setup_wifi3(peer, tid, 1, IEEE80211_SEQ_MAX);
}
}
pdev0 = soc->pdev_list[0];/* Hard code 0th elem */
if (pdev0) {
vdev0 = (struct dp_vdev *)TAILQ_FIRST(&pdev0->vdev_list);
if (vdev0 && vdev0->osif_rx) {
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_INFO,
FL("pdev0 %p vdev0 %p osif_rx %p"), pdev0, vdev0,
vdev0->osif_rx);
vdev0->osif_rx(vdev0->osif_vdev, nbuf);
} else {
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("INVALID vdev0 %p OR osif_rx"), vdev0);
}
} else {
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("INVALID pdev %p"), pdev0);
}
dp_rx_add_to_free_desc_list(head, tail, rx_desc);
return rx_bufs_used;
}
/**
* dp_rx_link_desc_return() - Return a MPDU link descriptor to HW
* (WBM), following error handling
*
* @soc: core DP main context
* @ring_desc: opaque pointer to the REO error ring descriptor
*
* Return: QDF_STATUS
*/
static QDF_STATUS
dp_rx_link_desc_return(struct dp_soc *soc, void *ring_desc)
{
void *buf_addr_info = HAL_RX_REO_BUF_ADDR_INFO_GET(ring_desc);
struct dp_srng *wbm_desc_rel_ring = &soc->wbm_desc_rel_ring;
void *wbm_rel_srng = wbm_desc_rel_ring->hal_srng;
void *hal_soc = soc->hal_soc;
QDF_STATUS status = QDF_STATUS_E_FAILURE;
void *src_srng_desc;
if (!wbm_rel_srng) {
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
"WBM RELEASE RING not initialized");
return status;
}
if (qdf_unlikely(hal_srng_access_start(hal_soc, wbm_rel_srng))) {
/* TODO */
/*
* Need API to convert from hal_ring pointer to
* Ring Type / Ring Id combo
*/
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("HAL RING Access For WBM Release SRNG Failed - %p"),
wbm_rel_srng);
goto done;
}
src_srng_desc = hal_srng_src_get_next(hal_soc, wbm_rel_srng);
if (qdf_likely(src_srng_desc)) {
/* Return link descriptor through WBM ring (SW2WBM)*/
hal_rx_msdu_link_desc_set(hal_soc,
src_srng_desc, buf_addr_info);
status = QDF_STATUS_SUCCESS;
} else {
struct hal_srng *srng = (struct hal_srng *)wbm_rel_srng;
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("WBM Release Ring (Id %d) Full"), srng->ring_id);
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
"HP 0x%x Reap HP 0x%x TP 0x%x Cached TP 0x%x",
*srng->u.src_ring.hp_addr, srng->u.src_ring.reap_hp,
*srng->u.src_ring.tp_addr, srng->u.src_ring.cached_tp);
}
done:
hal_srng_access_end(hal_soc, wbm_rel_srng);
return status;
}
/**
* dp_rx_err_process() - Processes error frames routed to REO error ring
*
* @soc: core txrx main context
* @hal_ring: opaque pointer to the HAL Rx Error Ring, which will be serviced
* @quota: No. of units (packets) that can be serviced in one shot.
*
* This function implements error processing and top level demultiplexer
* for all the frames routed to REO error ring.
*
* Return: uint32_t: No. of elements processed
*/
uint32_t
dp_rx_err_process(struct dp_soc *soc, void *hal_ring, uint32_t quota)
{
void *hal_soc;
void *ring_desc;
union dp_rx_desc_list_elem_t *head = NULL;
union dp_rx_desc_list_elem_t *tail = NULL;
uint32_t rx_bufs_used = 0;
uint8_t buf_type;
uint8_t error, rbm;
struct hal_rx_mpdu_desc_info mpdu_desc_info;
struct hal_buf_info hbi;
/* Debug -- Remove later */
qdf_assert(soc && hal_ring);
hal_soc = soc->hal_soc;
/* Debug -- Remove later */
qdf_assert(hal_soc);
if (qdf_unlikely(hal_srng_access_start(hal_soc, hal_ring))) {
/* TODO */
/*
* Need API to convert from hal_ring pointer to
* Ring Type / Ring Id combo
*/
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("HAL RING Access Failed -- %p"), hal_ring);
goto done;
}
while (qdf_likely((ring_desc =
hal_srng_dst_get_next(hal_soc, hal_ring))
&& quota--)) {
error = HAL_RX_ERROR_STATUS_GET(ring_desc);
qdf_assert(error == HAL_REO_ERROR_DETECTED);
/*
* Check if the buffer is to be processed on this processor
*/
rbm = hal_rx_ret_buf_manager_get(ring_desc);
if (qdf_unlikely(rbm != HAL_RX_BUF_RBM_SW3_BM)) {
/* TODO */
/* Call appropriate handler */
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("Invalid RBM %d"), rbm);
continue;
}
buf_type = HAL_RX_REO_BUF_TYPE_GET(ring_desc);
/*
* For REO error ring, expect only MSDU LINK DESC
*/
qdf_assert(buf_type == HAL_RX_REO_MSDU_LINK_DESC_TYPE);
hal_rx_reo_buf_paddr_get(ring_desc, &hbi);
/* Get the MPDU DESC info */
hal_rx_mpdu_desc_info_get(ring_desc, &mpdu_desc_info);
if (mpdu_desc_info.mpdu_flags & HAL_MPDU_F_FRAGMENT) {
/* TODO */
rx_bufs_used += dp_rx_frag_handle(soc,
ring_desc, &mpdu_desc_info,
&head, &tail, quota);
continue;
}
if (hal_rx_reo_is_pn_error(ring_desc)) {
/* TOD0 */
rx_bufs_used += dp_rx_pn_error_handle(soc,
ring_desc, &mpdu_desc_info,
&head, &tail, quota);
continue;
}
if (hal_rx_reo_is_2k_jump(ring_desc)) {
/* TOD0 */
rx_bufs_used += dp_rx_2k_jump_handle(soc,
ring_desc, &mpdu_desc_info,
&head, &tail, quota);
continue;
}
/* Return link descriptor through WBM ring (SW2WBM)*/
dp_rx_link_desc_return(soc, ring_desc);
}
done:
hal_srng_access_end(hal_soc, hal_ring);
/* Assume MAC id = 0, owner = 0 */
if (rx_bufs_used)
dp_rx_buffers_replenish(soc, 0, rx_bufs_used, &head, &tail,
HAL_RX_BUF_RBM_SW3_BM);
return rx_bufs_used; /* Assume no scale factor for now */
}
/**
* dp_rx_wbm_err_process() - Processes error frames routed to WBM release ring
*
* @soc: core txrx main context
* @hal_ring: opaque pointer to the HAL Rx Error Ring, which will be serviced
* @quota: No. of units (packets) that can be serviced in one shot.
*
* This function implements error processing and top level demultiplexer
* for all the frames routed to WBM2HOST sw release ring.
*
* Return: uint32_t: No. of elements processed
*/
uint32_t
dp_rx_wbm_err_process(struct dp_soc *soc, void *hal_ring, uint32_t quota)
{
void *hal_soc;
void *ring_desc;
struct dp_rx_desc *rx_desc;
union dp_rx_desc_list_elem_t *head = NULL;
union dp_rx_desc_list_elem_t *tail = NULL;
uint32_t rx_bufs_used = 0;
uint8_t buf_type, rbm;
uint8_t wbm_err_src;
uint32_t rx_buf_cookie;
/* Debug -- Remove later */
qdf_assert(soc && hal_ring);
hal_soc = soc->hal_soc;
/* Debug -- Remove later */
qdf_assert(hal_soc);
if (qdf_unlikely(hal_srng_access_start(hal_soc, hal_ring))) {
/* TODO */
/*
* Need API to convert from hal_ring pointer to
* Ring Type / Ring Id combo
*/
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("HAL RING Access Failed -- %p"), hal_ring);
goto done;
}
while (qdf_likely((ring_desc =
hal_srng_dst_get_next(hal_soc, hal_ring))
&& quota--)) {
/* XXX */
wbm_err_src = HAL_RX_WBM_ERR_SRC_GET(ring_desc);
qdf_assert((wbm_err_src == HAL_RX_WBM_ERR_SRC_RXDMA) ||
(wbm_err_src == HAL_RX_WBM_ERR_SRC_REO));
/*
* Check if the buffer is to be processed on this processor
*/
rbm = hal_rx_ret_buf_manager_get(ring_desc);
if (qdf_unlikely(rbm != HAL_RX_BUF_RBM_SW3_BM)) {
/* TODO */
/* Call appropriate handler */
QDF_TRACE(QDF_MODULE_ID_DP, QDF_TRACE_LEVEL_ERROR,
FL("Invalid RBM %d"), rbm);
continue;
}
/* XXX */
buf_type = HAL_RX_WBM_BUF_TYPE_GET(ring_desc);
/*
* For WBM ring, expect only MSDU buffers
*/
qdf_assert(buf_type == HAL_RX_WBM_BUF_TYPE_REL_BUF);
if (wbm_err_src == HAL_RX_WBM_ERR_SRC_REO) {
uint8_t push_reason =
HAL_RX_WBM_REO_PUSH_REASON_GET(ring_desc);
if (push_reason == HAL_RX_WBM_REO_PSH_RSN_ERROR) {
uint8_t reo_error_code =
HAL_RX_WBM_REO_ERROR_CODE_GET(ring_desc);
switch (reo_error_code) {
/*
* Handling for packets which have NULL REO
* queue descriptor
*/
case HAL_REO_ERR_QUEUE_DESC_ADDR_0:
QDF_TRACE(QDF_MODULE_ID_DP,
QDF_TRACE_LEVEL_WARN,
"Got pkt with REO ERROR: %d",
reo_error_code);
rx_bufs_used +=
dp_rx_null_q_desc_handle(soc,
ring_desc, &head, &tail, quota);
continue;
/* TODO */
/* Add per error code accounting */
default:
QDF_TRACE(QDF_MODULE_ID_DP,
QDF_TRACE_LEVEL_ERROR,
"REO error %d detected",
reo_error_code);
}
}
} else if (wbm_err_src == HAL_RX_WBM_ERR_SRC_RXDMA) {
uint8_t push_reason =
HAL_RX_WBM_RXDMA_PUSH_REASON_GET(ring_desc);
if (push_reason == HAL_RX_WBM_RXDMA_PSH_RSN_ERROR) {
uint8_t rxdma_error_code =
HAL_RX_WBM_RXDMA_ERROR_CODE_GET(ring_desc);
switch (rxdma_error_code) {
/* TODO */
/* Add per error code accounting */
default:
QDF_TRACE(QDF_MODULE_ID_DP,
QDF_TRACE_LEVEL_ERROR,
"RXDMA error %d detected",
rxdma_error_code);
}
}
} else {
/* Should not come here */
qdf_assert(0);
}
rx_buf_cookie = HAL_RX_WBM_BUF_COOKIE_GET(ring_desc);
rx_desc = dp_rx_cookie_2_va(soc, rx_buf_cookie);
qdf_assert(rx_desc);
rx_bufs_used++;
qdf_nbuf_unmap_single(soc->osdev, rx_desc->nbuf,
QDF_DMA_BIDIRECTIONAL);
qdf_nbuf_free(rx_desc->nbuf);
dp_rx_add_to_free_desc_list(&head, &tail, rx_desc);
}
done:
hal_srng_access_end(hal_soc, hal_ring);
/* Assume MAC id = 0, owner = 0 */
if (rx_bufs_used)
dp_rx_buffers_replenish(soc, 0, rx_bufs_used, &head, &tail,
HAL_RX_BUF_RBM_SW3_BM);
return rx_bufs_used; /* Assume no scale factor for now */
}