[PATCH 3/4] Revert "Bluetooth: btusb: Configure altsetting for HCI_USER_CHANNEL"

[Hsin-chen Chuang <chharry@google.com>]

From: Hsin-chen Chuang <chharry@chromium.org>

This reverts commit 75ddcd5ad40ecd9fbc9f5a7a2ed0e1e74921db3c.

This patch doesn't work quite well - It's observed that with this patch
HFP is flaky on most of the existing USB Bluetooth controllers: Intel
chips sometimes send out no packet for Transparent codec; MTK chips may
generate SCO data with a wrong handle for CVSD codec; RTK could split
the data with a wrong packet size for Transparent codec; ... etc.

Cc: chromeos-bluetooth-upstreaming@chromium.org
Signed-off-by: Hsin-chen Chuang <chharry@chromium.org>
---

 drivers/bluetooth/Kconfig | 12 ------------
 drivers/bluetooth/btusb.c | 41 ---------------------------------------
 2 files changed, 53 deletions(-)

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 7771edf54fb3..4ab32abf0f48 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -56,18 +56,6 @@ config BT_HCIBTUSB_POLL_SYNC
 	  Say Y here to enable USB poll_sync for Bluetooth USB devices by
 	  default.
 
-config BT_HCIBTUSB_AUTO_ISOC_ALT
-	bool "Automatically adjust alternate setting for Isoc endpoints"
-	depends on BT_HCIBTUSB
-	default y if CHROME_PLATFORMS
-	help
-	  Say Y here to automatically adjusting the alternate setting for
-	  HCI_USER_CHANNEL whenever a SCO link is established.
-
-	  When enabled, btusb intercepts the HCI_EV_SYNC_CONN_COMPLETE packets
-	  and configures isoc endpoint alternate setting automatically when
-	  HCI_USER_CHANNEL is in use.
-
 config BT_HCIBTUSB_BCM
 	bool "Broadcom protocol support"
 	depends on BT_HCIBTUSB
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index fcaee5cd728b..b7040747b890 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -35,7 +35,6 @@ static bool force_scofix;
 static bool enable_autosuspend = IS_ENABLED(CONFIG_BT_HCIBTUSB_AUTOSUSPEND);
 static bool enable_poll_sync = IS_ENABLED(CONFIG_BT_HCIBTUSB_POLL_SYNC);
 static bool reset = true;
-static bool auto_isoc_alt = IS_ENABLED(CONFIG_BT_HCIBTUSB_AUTO_ISOC_ALT);
 
 static struct usb_driver btusb_driver;
 
@@ -1121,42 +1120,6 @@ static inline void btusb_free_frags(struct btusb_data *data)
 	spin_unlock_irqrestore(&data->rxlock, flags);
 }
 
-static void btusb_sco_connected(struct btusb_data *data, struct sk_buff *skb)
-{
-	struct hci_event_hdr *hdr = (void *) skb->data;
-	struct hci_ev_sync_conn_complete *ev =
-		(void *) skb->data + sizeof(*hdr);
-	struct hci_dev *hdev = data->hdev;
-	unsigned int notify_air_mode;
-
-	if (hci_skb_pkt_type(skb) != HCI_EVENT_PKT)
-		return;
-
-	if (skb->len < sizeof(*hdr) || hdr->evt != HCI_EV_SYNC_CONN_COMPLETE)
-		return;
-
-	if (skb->len != sizeof(*hdr) + sizeof(*ev) || ev->status)
-		return;
-
-	switch (ev->air_mode) {
-	case BT_CODEC_CVSD:
-		notify_air_mode = HCI_NOTIFY_ENABLE_SCO_CVSD;
-		break;
-
-	case BT_CODEC_TRANSPARENT:
-		notify_air_mode = HCI_NOTIFY_ENABLE_SCO_TRANSP;
-		break;
-
-	default:
-		return;
-	}
-
-	bt_dev_info(hdev, "enabling SCO with air mode %u", ev->air_mode);
-	data->sco_num = 1;
-	data->air_mode = notify_air_mode;
-	schedule_work(&data->work);
-}
-
 static int btusb_recv_event(struct btusb_data *data, struct sk_buff *skb)
 {
 	if (data->intr_interval) {
@@ -1164,10 +1127,6 @@ static int btusb_recv_event(struct btusb_data *data, struct sk_buff *skb)
 		schedule_delayed_work(&data->rx_work, 0);
 	}
 
-	/* Configure altsetting for HCI_USER_CHANNEL on SCO connected */
-	if (auto_isoc_alt && hci_dev_test_flag(data->hdev, HCI_USER_CHANNEL))
-		btusb_sco_connected(data, skb);
-
 	return data->recv_event(data->hdev, skb);
 }
 
-- 
2.49.0.604.gff1f9ca942-goog