[PATCH] Bluetooth: add quirk disabling query LE tx power

From: Orlando Chamberlain
Date: Thu Sep 30 2021 - 10:14:10 EST


Querying LE tx power on startup broke Bluetooth on some Broadcom chips
in Apple computers (at least MacBookPro16,1 and iMac20,1). Added a quirk
disabling this query for affected devices, based off their common chip
id 150. Affected devices will not be able to query LE tx power, however
they were not doing this before.

Fixes: 7c395ea521e6m ("Bluetooth: Query LE tx power on startup")
Signed-off-by: Orlando Chamberlain <redecorating@xxxxxxxxxxxxxx>
---
drivers/bluetooth/btbcm.c | 4 ++++
include/net/bluetooth/hci.h | 8 ++++++++
net/bluetooth/hci_core.c | 3 ++-
3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index e4182acee488..4ecc50d93107 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/drivers/bluetooth/btbcm.c
@@ -353,6 +353,10 @@ static int btbcm_read_info(struct hci_dev *hdev)
return PTR_ERR(skb);

bt_dev_info(hdev, "BCM: chip id %u", skb->data[1]);
+
+ if (skb->data[1] == 150)
+ set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
+
kfree_skb(skb);

/* Read Controller Features */
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index b80415011dcd..5e0dd0c39ade 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -246,6 +246,14 @@ enum {
* HCI after resume.
*/
HCI_QUIRK_NO_SUSPEND_NOTIFIER,
+
+ /*
+ * When this quirk is set, LE tx power is not queried on startup.
+ *
+ * This quirk can be set before hci_register_dev is called or
+ * during the hdev->setup vendor callback.
+ */
+ HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER,
};

/* HCI device flags */
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 8a47a3017d61..16e39739c662 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -742,7 +742,8 @@ static int hci_init3_req(struct hci_request *req, unsigned long opt)
hci_req_add(req, HCI_OP_LE_READ_ADV_TX_POWER, 0, NULL);
}

- if (hdev->commands[38] & 0x80) {
+ if (hdev->commands[38] & 0x80 &&
+ !test_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks)) {
/* Read LE Min/Max Tx Power*/
hci_req_add(req, HCI_OP_LE_READ_TRANSMIT_POWER,
0, NULL);
--
2.33.0