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Bluetooth: controller: Consideration for SDU interval in fragmentation

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Included consideration for the packet sequence number and time stamps
together with the SDU interval in matching the event for fragmentation
of SDUs to unframed PDUs.

Implemented:
-- Increase in kconfig limit of BT_CTLR_ISO_TX_BUFFERS to allow full 32
   buffers to be available for LL/CIS/PER/BV-39C
-- ISO-AL microsecond time wrapping exposed to be used externally to
   adjust incoming Group Reference Points and Time-stamps where required
-- Function that handles adjustment of payload number according to
   incoming SDU exposed for external use to allow next payload number to
   be accessed by ISO transmit tests
-- Changed internal fragmentation source identification parameter from
   the source structure pointer to the source handle so that only the
   source handle needs to be used for external calls

Signed-off-by: Nirosharn Amarasinghe <niag@demant.com>
This commit is contained in:
Nirosharn Amarasinghe 2022-11-28 16:53:31 +01:00 • committed by Carles Cufí
commit 11ce28f8f7
7 changed files with 223 additions and 91 deletions
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55
subsys/bluetooth/controller/hci/hci.c
View file

@ -63,6 +63,7 @@
#include "ll_sw/ull_conn_iso_types.h"
#include "ll_sw/ull_conn_iso_internal.h"
#include "ll_sw/ull_df_types.h"
#include "ll_sw/ull_internal.h"
#include "ll_sw/ull_adv_internal.h"
#include "ll_sw/ull_sync_internal.h"
@ -5677,7 +5678,7 @@ int hci_iso_handle(struct net_buf *buf, struct net_buf **evt)
/* Overwrite time stamp with HCI provided time stamp */
time_stamp = net_buf_pull_mem(buf, sizeof(*time_stamp));
len -= sizeof(*time_stamp);
sdu_frag_tx.time_stamp = *time_stamp;
sdu_frag_tx.time_stamp = sys_le32_to_cpu(*time_stamp);
} else {
sdu_frag_tx.time_stamp =
HAL_TICKER_TICKS_TO_US(ticker_ticks_now_get());
@ -5687,8 +5688,8 @@ int hci_iso_handle(struct net_buf *buf, struct net_buf **evt)
if ((pb_flag & 0x01) == 0) {
iso_data_hdr = net_buf_pull_mem(buf, sizeof(*iso_data_hdr));
len -= sizeof(*iso_data_hdr);
sdu_frag_tx.packet_sn = iso_data_hdr->sn;
sdu_frag_tx.iso_sdu_length = iso_data_hdr->slen;
sdu_frag_tx.packet_sn = sys_le16_to_cpu(iso_data_hdr->sn);
sdu_frag_tx.iso_sdu_length = sys_le16_to_cpu(iso_data_hdr->slen);
} else {
sdu_frag_tx.packet_sn = 0;
sdu_frag_tx.iso_sdu_length = 0;
@ -5719,43 +5720,35 @@ int hci_iso_handle(struct net_buf *buf, struct net_buf **evt)
}
struct ll_conn_iso_group *cig = cis->group;
uint8_t event_offset;
hdr = &(cis->hdr);
/* Set target event as the current event. This might cause some
* misalignment between SDU interval and ISO interval in the
* case of a burst from the application or late release. However
* according to the specifications:
* BT Core V5.3 : Vol 6 Low Energy Controller : Part B LL Spec:
* 4.5.13.3 Connected Isochronous Data:
* This burst is associated with the corresponding CIS event but
* the payloads may be transmitted in later events as well.
* If flush timeout is greater than one, use the current event,
* otherwise postpone to the next.
/* We must ensure sufficient time for ISO-AL to fragment SDU and
* deliver PDUs to the TX queue. By checking ull_ref_get, we
* know if we are within the subevents of an ISO event. If so,
* we can assume that we have enough time to deliver in the next
* ISO event. If we're not active within the ISO event, we don't
* know if there is enough time to deliver in the next event,
* and for safety we set the target to current event + 2.
*
* TODO: Calculate the best possible target event based on CIS
* reference, FT and event_count.
* For FT > 1, we have the opportunity to retransmit in later
* event(s), in which case we have the option to target an
* earlier event (this or next) because being late does not
* instantly flush the payload.
*/
sdu_frag_tx.target_event = cis->lll.event_count +
((cis->lll.tx.ft > 1U) ? 0U : 1U);
/* FIXME: Remove the below temporary hack to buffer up ISO data
* if the SDU interval and ISO interval misalign.
*/
uint64_t pkt_seq_num = cis->lll.event_count + 1U;
event_offset = ull_ref_get(&cig->ull) ? 1 : 2;
if (((pkt_seq_num - cis->lll.tx.payload_count) &
BIT64_MASK(39)) <= BIT64_MASK(38)) {
cis->lll.tx.payload_count = pkt_seq_num;
} else {
pkt_seq_num = cis->lll.tx.payload_count;
if (cis->lll.tx.ft > 1) {
/* FT > 1, target an earlier event */
event_offset -= 1;
}
sdu_frag_tx.target_event = pkt_seq_num;
cis->lll.tx.payload_count++;
sdu_frag_tx.grp_ref_point = cig->cig_ref_point;
sdu_frag_tx.target_event = cis->lll.event_count + event_offset;
sdu_frag_tx.grp_ref_point = isoal_get_wrapped_time_us(cig->cig_ref_point,
(event_offset * cig->iso_interval *
ISO_INT_UNIT_US));
/* Get controller's input data path for CIS */
dp_in = hdr->datapath_in;