From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This enables buffer flow control for SCO/eSCO
(see: Bluetooth Core 6.0 spec: 6.22. Synchronous Flow Control Enable),
recently this has caused the following problem and is actually a nice
addition for the likes of Socket TX complete:
< HCI Command: Read Buffer Size (0x04|0x0005) plen 0
> HCI Event: Command Complete (0x0e) plen 11
Read Buffer Size (0x04|0x0005) ncmd 1
Status: Success (0x00)
ACL MTU: 1021 ACL max packet: 5
SCO MTU: 240 SCO max packet: 8
...
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
> HCI Event: Hardware Error (0x10) plen 1
Code: 0x0a
To fix the code will now attempt to enable buffer flow control:
< HCI Command: Write Sync Fl.. (0x03|0x002f) plen 1
Flow control: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4
Write Sync Flow Control Enable (0x03|0x002f) ncmd 1
Status: Success (0x00)
And then test it by sending an empty packet to confirm the controller
will generate HCI_EV_NUM_COMP_PKTS events:
sco-tester[40]: < SCO Data TX:.. flags 0x00 dlen 9
> HCI Event: Number of Completed P.. (0x13) plen 5
Num handles: 1
Handle: 42 Address: 00:AA:01:01:00:00 (Intel Corporation)
Count: 1
#103: len 10 (40 Kb/s)
Latency: 2 msec (2-2 msec ~2 msec)
Fixes: 7fedd3bb6b77 ("Bluetooth: Prioritize SCO traffic")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
include/net/bluetooth/hci.h | 13 +++++++
include/net/bluetooth/hci_core.h | 1 +
net/bluetooth/hci_core.c | 67 ++++++++++++++++----------------
net/bluetooth/hci_event.c | 2 +
net/bluetooth/hci_sync.c | 24 ++++++++++++
5 files changed, 74 insertions(+), 33 deletions(-)
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index b99818df8ee7..3c8f95174fcf 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -208,6 +208,13 @@ enum {
*/
HCI_QUIRK_WIDEBAND_SPEECH_SUPPORTED,
+ /* When this quirk is set consider Sync Flow Control as supported by
+ * the driver.
+ *
+ * This quirk must be set before hci_register_dev is called.
+ */
+ HCI_QUIRK_SYNC_FLOWCTL_SUPPORTED,
+
/* When this quirk is set, the LE states reported through the
* HCI_LE_READ_SUPPORTED_STATES are invalid/broken.
*
@@ -448,6 +455,7 @@ enum {
HCI_WIDEBAND_SPEECH_ENABLED,
HCI_EVENT_FILTER_CONFIGURED,
HCI_PA_SYNC,
+ HCI_SCO_FLOWCTL,
HCI_DUT_MODE,
HCI_VENDOR_DIAG,
@@ -1544,6 +1552,11 @@ struct hci_rp_read_tx_power {
__s8 tx_power;
} __packed;
+#define HCI_OP_WRITE_SYNC_FLOWCTL 0x0c2f
+struct hci_cp_write_sync_flowctl {
+ __u8 enable;
+} __packed;
+
#define HCI_OP_READ_PAGE_SCAN_TYPE 0x0c46
struct hci_rp_read_page_scan_type {
__u8 status;
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 7966db4038cc..f78e4298e39a 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1858,6 +1858,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
#define lmp_hold_capable(dev) ((dev)->features[0][0] & LMP_HOLD)
#define lmp_sniff_capable(dev) ((dev)->features[0][0] & LMP_SNIFF)
#define lmp_park_capable(dev) ((dev)->features[0][1] & LMP_PARK)
+#define lmp_sco_capable(dev) ((dev)->features[0][1] & LMP_SCO)
#define lmp_inq_rssi_capable(dev) ((dev)->features[0][3] & LMP_RSSI_INQ)
#define lmp_esco_capable(dev) ((dev)->features[0][3] & LMP_ESCO)
#define lmp_bredr_capable(dev) (!((dev)->features[0][4] & LMP_NO_BREDR))
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 012fc107901a..efba2b539902 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3552,51 +3552,52 @@ static void __check_timeout(struct hci_dev *hdev, unsigned int cnt, u8 type)
}
/* Schedule SCO */
-static void hci_sched_sco(struct hci_dev *hdev)
+static void hci_sched_sco_type(struct hci_dev *hdev, __u8 type)
{
struct hci_conn *conn;
struct sk_buff *skb;
int quote;
+ unsigned int pkts;
- BT_DBG("%s", hdev->name);
+ bt_dev_dbg(hdev, "type %u", type);
- if (!hci_conn_num(hdev, SCO_LINK))
+ if (!hci_conn_num(hdev, type))
return;
- while (hdev->sco_cnt && (conn = hci_low_sent(hdev, SCO_LINK, "e))) {
+ /* Use sco_pkts if flow control has not been enabled yet which will
+ * limit the amount of buffer sent in a row.
+ */
+ if (!hci_dev_test_flag(hdev, HCI_SCO_FLOWCTL))
+ pkts = hdev->sco_pkts;
+ else
+ pkts = hdev->sco_cnt;
+
+ if (!pkts)
+ return;
+
+ while (pkts && (conn = hci_low_sent(hdev, type, "e))) {
while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
BT_DBG("skb %p len %d", skb, skb->len);
hci_send_frame(hdev, skb);
+ pkts--;
+
+ if (hdev->sco_cnt > 0)
+ hdev->sco_cnt--;
+
conn->sent++;
if (conn->sent == ~0)
conn->sent = 0;
}
}
-}
-static void hci_sched_esco(struct hci_dev *hdev)
-{
- struct hci_conn *conn;
- struct sk_buff *skb;
- int quote;
-
- BT_DBG("%s", hdev->name);
-
- if (!hci_conn_num(hdev, ESCO_LINK))
- return;
-
- while (hdev->sco_cnt && (conn = hci_low_sent(hdev, ESCO_LINK,
- "e))) {
- while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
- BT_DBG("skb %p len %d", skb, skb->len);
- hci_send_frame(hdev, skb);
-
- conn->sent++;
- if (conn->sent == ~0)
- conn->sent = 0;
- }
- }
+ /* Rescheduled if all packets were sent and flow control is not enabled
+ * as there could be more packets queued that could not be sent and
+ * since no HCI_EV_NUM_COMP_PKTS event will be generated the reschedule
+ * needs to be forced.
+ */
+ if (!pkts && !hci_dev_test_flag(hdev, HCI_SCO_FLOWCTL))
+ queue_work(hdev->workqueue, &hdev->tx_work);
}
static void hci_sched_acl_pkt(struct hci_dev *hdev)
@@ -3632,8 +3633,8 @@ static void hci_sched_acl_pkt(struct hci_dev *hdev)
chan->conn->sent++;
/* Send pending SCO packets right away */
- hci_sched_sco(hdev);
- hci_sched_esco(hdev);
+ hci_sched_sco_type(hdev, SCO_LINK);
+ hci_sched_sco_type(hdev, ESCO_LINK);
}
}
@@ -3688,8 +3689,8 @@ static void hci_sched_le(struct hci_dev *hdev)
chan->conn->sent++;
/* Send pending SCO packets right away */
- hci_sched_sco(hdev);
- hci_sched_esco(hdev);
+ hci_sched_sco_type(hdev, SCO_LINK);
+ hci_sched_sco_type(hdev, ESCO_LINK);
}
}
@@ -3734,8 +3735,8 @@ static void hci_tx_work(struct work_struct *work)
if (!hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) {
/* Schedule queues and send stuff to HCI driver */
- hci_sched_sco(hdev);
- hci_sched_esco(hdev);
+ hci_sched_sco_type(hdev, SCO_LINK);
+ hci_sched_sco_type(hdev, ESCO_LINK);
hci_sched_iso(hdev);
hci_sched_acl(hdev);
hci_sched_le(hdev);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 19e19c9f5e68..6d0138b778aa 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4445,9 +4445,11 @@ static void hci_num_comp_pkts_evt(struct hci_dev *hdev, void *data,
break;
case SCO_LINK:
+ case ESCO_LINK:
hdev->sco_cnt += count;
if (hdev->sco_cnt > hdev->sco_pkts)
hdev->sco_cnt = hdev->sco_pkts;
+
break;
case ISO_LINK:
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index c4c2cf51b219..609b035e5c90 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -3769,6 +3769,28 @@ static int hci_write_ca_timeout_sync(struct hci_dev *hdev)
sizeof(param), ¶m, HCI_CMD_TIMEOUT);
}
+/* Enable SCO flow control if supported */
+static int hci_write_sync_flowctl_sync(struct hci_dev *hdev)
+{
+ struct hci_cp_write_sync_flowctl cp;
+ int err;
+
+ /* Check if the controller supports SCO and HCI_OP_WRITE_SYNC_FLOWCTL */
+ if (!lmp_sco_capable(hdev) || !(hdev->commands[10] & BIT(4)) ||
+ !test_bit(HCI_QUIRK_SYNC_FLOWCTL_SUPPORTED, &hdev->quirks))
+ return 0;
+
+ memset(&cp, 0, sizeof(cp));
+ cp.enable = 0x01;
+
+ err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_SYNC_FLOWCTL,
+ sizeof(cp), &cp, HCI_CMD_TIMEOUT);
+ if (!err)
+ hci_dev_set_flag(hdev, HCI_SCO_FLOWCTL);
+
+ return err;
+}
+
/* BR Controller init stage 2 command sequence */
static const struct hci_init_stage br_init2[] = {
/* HCI_OP_READ_BUFFER_SIZE */
@@ -3787,6 +3809,8 @@ static const struct hci_init_stage br_init2[] = {
HCI_INIT(hci_clear_event_filter_sync),
/* HCI_OP_WRITE_CA_TIMEOUT */
HCI_INIT(hci_write_ca_timeout_sync),
+ /* HCI_OP_WRITE_SYNC_FLOWCTL */
+ HCI_INIT(hci_write_sync_flowctl_sync),
{}
};
--
2.48.1
