[PATCH] Bluetooth: hci_sync: fix LE init stage 3 failure

[André Groenewald]

A controller may indicate support for the extended advertising feature but
doesn't support the HCI_LE_Read_Number_of_Supported_Advertising_Sets
command, which will cause the initialization to fail.

Signed-off-by: André Groenewald <andre.groenewald@xxxxxxxxxxxxxxxxxxx>
---
 net/bluetooth/hci_sync.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index c86f4e42e69c..c07be5813113 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4416,6 +4416,15 @@ static int hci_le_read_num_support_adv_sets_sync(struct hci_dev *hdev)
 	if (!ext_adv_capable(hdev))
 		return 0;
 
+	/* Checking for extended advertising capabilities is not enough; refine
+	 * by checking if the HCI_LE_Read_Number_of_Supported_Advertising_Sets
+	 * command is supported. Since this command is part of the LE init
+	 * stage 3, the initialization will fail whenever the command is not
+	 * supported for devices that indicate extended advertising features.
+	 */
+	if (!(hdev->commands[36] & 0x80))
+		return 0;
+
 	return __hci_cmd_sync_status(hdev,
 				     HCI_OP_LE_READ_NUM_SUPPORTED_ADV_SETS,
 				     0, NULL, HCI_CMD_TIMEOUT);
-- 
2.34.1