[PATCH v9 1/2] Bluetooth: add quirk disabling LE Read Transmit Power

From: Aditya Garg
Date: Thu Dec 02 2021 - 05:15:38 EST


From: Aditya Garg <gargaditya08@xxxxxxxx>

Some devices have a bug causing them to not work if they query
LE tx power on startup. Thus we add a quirk in order to not query it
and default min/max tx power values to HCI_TX_POWER_INVALID.

Signed-off-by: Aditya Garg <gargaditya08@xxxxxxxx>
Reported-by: Orlando Chamberlain <redecorating@xxxxxxxxxxxxxx>
Tested-by: Orlando Chamberlain <redecorating@xxxxxxxxxxxxxx>
Link:
https://lore.kernel.org/r/4970a940-211b-25d6-edab-21a815313954@xxxxxxxxxxxxxx
Fixes: 7c395ea521e6 ("Bluetooth: Query LE tx power on startup")
Cc: stable@xxxxxxxxxxxxxxx
---
v7 :- Added Tested-by.
v8 :- Fix checkpatch error.
v9 :- Remake patch for Bluetooth-next tree and add Cc: stable@xxxxxxxxxxxxxxx
include/net/bluetooth/hci.h | 9 +++++++++
net/bluetooth/hci_sync.c | 3 ++-
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 0d2a92168..c4959cf9a 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -246,6 +246,15 @@ enum {
* HCI after resume.
*/
HCI_QUIRK_NO_SUSPEND_NOTIFIER,
+
+ /*
+ * When this quirk is set, LE tx power is not queried on startup
+ * and the min/max tx power values default to HCI_TX_POWER_INVALID.
+ *
+ * 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_sync.c b/net/bluetooth/hci_sync.c
index ad86caf41..52e6b5dae 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -3283,7 +3283,8 @@ static int hci_le_read_adv_tx_power_sync(struct hci_dev *hdev)
/* Read LE Min/Max Tx Power*/
static int hci_le_read_tx_power_sync(struct hci_dev *hdev)
{
- if (!(hdev->commands[38] & 0x80))
+ if (!(hdev->commands[38] & 0x80) ||
+ test_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks))
return 0;

return __hci_cmd_sync_status(hdev, HCI_OP_LE_READ_TRANSMIT_POWER,
--
2.25.1