diff mbox series

[v1] Bluetooth: hci_event: Fix setting of unicast qos interval

Message ID 20240606162917.621031-1-luiz.dentz@gmail.com
State New
Headers show
Series [v1] Bluetooth: hci_event: Fix setting of unicast qos interval | expand

Commit Message

Luiz Augusto von Dentz June 6, 2024, 4:29 p.m. UTC 
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

qos->ucast interval reffers to the SDU interval, and should not
be set to the interval value reported by the LE CIS Established
event since the latter reffers to the ISO interval. These two
interval are not the same thing:

BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 6, Part G

Isochronous interval:
The time between two consecutive BIS or CIS events (designated
ISO_Interval in the Link Layer)

SDU interval:
The nominal time between two consecutive SDUs that are sent or
received by the upper layer.

So this instead uses the following formula from the spec to calculate
the resulting SDU interface:

BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 6, Part G
page 3075:

Transport_Latency_C_To_P = CIG_Sync_Delay + (FT_C_To_P) ×
ISO_Interval + SDU_Interval_C_To_P
Transport_Latency_P_To_C = CIG_Sync_Delay + (FT_P_To_C) ×
ISO_Interval + SDU_Interval_P_To_C

Link: https://github.com/bluez/bluez/issues/823
Fixes: 2be22f1941d5 ("Bluetooth: hci_event: Fix parsing of CIS Established Event")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/hci_event.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

Comments

patchwork-bot+bluetooth@kernel.org June 10, 2024, 2:03 p.m. UTC | #1 
Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Thu,  6 Jun 2024 12:29:17 -0400 you wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> 
> qos->ucast interval reffers to the SDU interval, and should not
> be set to the interval value reported by the LE CIS Established
> event since the latter reffers to the ISO interval. These two
> interval are not the same thing:
> 
> [...]

Here is the summary with links:
  - [v1] Bluetooth: hci_event: Fix setting of unicast qos interval
    https://git.kernel.org/bluetooth/bluetooth-next/c/9b70755997d3

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index da10738a052d..5d23bcf18716 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -6667,6 +6667,7 @@  static void hci_le_cis_estabilished_evt(struct hci_dev *hdev, void *data,
 	struct bt_iso_qos *qos;
 	bool pending = false;
 	u16 handle = __le16_to_cpu(ev->handle);
+	u32 c_sdu_interval, p_sdu_interval;
 
 	bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);
 
@@ -6691,12 +6692,25 @@  static void hci_le_cis_estabilished_evt(struct hci_dev *hdev, void *data,
 
 	pending = test_and_clear_bit(HCI_CONN_CREATE_CIS, &conn->flags);
 
-	/* Convert ISO Interval (1.25 ms slots) to SDU Interval (us) */
-	qos->ucast.in.interval = le16_to_cpu(ev->interval) * 1250;
-	qos->ucast.out.interval = qos->ucast.in.interval;
+	/* BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 6, Part G
+	 * page 3075:
+	 * Transport_Latency_C_To_P = CIG_Sync_Delay + (FT_C_To_P) ×
+	 * ISO_Interval + SDU_Interval_C_To_P
+	 * ...
+	 * SDU_Interval = (CIG_Sync_Delay + (FT) x ISO_Interval) -
+	 *					Transport_Latency
+	 */
+	c_sdu_interval = (get_unaligned_le24(ev->cig_sync_delay) +
+			 (ev->c_ft * le16_to_cpu(ev->interval) * 1250)) -
+			get_unaligned_le24(ev->c_latency);
+	p_sdu_interval = (get_unaligned_le24(ev->cig_sync_delay) +
+			 (ev->p_ft * le16_to_cpu(ev->interval) * 1250)) -
+			get_unaligned_le24(ev->p_latency);
 
 	switch (conn->role) {
 	case HCI_ROLE_SLAVE:
+		qos->ucast.in.interval = c_sdu_interval;
+		qos->ucast.out.interval = p_sdu_interval;
 		/* Convert Transport Latency (us) to Latency (msec) */
 		qos->ucast.in.latency =
 			DIV_ROUND_CLOSEST(get_unaligned_le24(ev->c_latency),
@@ -6710,6 +6724,8 @@  static void hci_le_cis_estabilished_evt(struct hci_dev *hdev, void *data,
 		qos->ucast.out.phy = ev->p_phy;
 		break;
 	case HCI_ROLE_MASTER:
+		qos->ucast.in.interval = p_sdu_interval;
+		qos->ucast.out.interval = c_sdu_interval;
 		/* Convert Transport Latency (us) to Latency (msec) */
 		qos->ucast.out.latency =
 			DIV_ROUND_CLOSEST(get_unaligned_le24(ev->c_latency),