Bluetooth: btbcm: disable read tx power for some Macs with the T2 Security chip

Some Macs with the T2 security chip had Bluetooth not working.
To fix it we add DMI based quirks to disable querying of LE Tx power.
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Reported-by: Orlando Chamberlain <redecorating@protonmail.com>
Tested-by: Orlando Chamberlain <redecorating@protonmail.com>
Link:
https://lore.kernel.org/r/4970a940-211b-25d6-edab-21a815313954@protonmail.com
Fixes: 7c395ea5 ("Bluetooth: Query LE tx power on startup")
Cc: stable@vger.kernel.org
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btbcm.c

@@ -8,6 +8,7 @@
 
 #include <linux/module.h>
 #include <linux/firmware.h>
+#include <linux/dmi.h>
 #include <asm/unaligned.h>
 
 #include <net/bluetooth/bluetooth.h>
@@ -343,6 +344,40 @@ static struct sk_buff *btbcm_read_usb_product(struct hci_dev *hdev)
 	return skb;
 }
 
+static const struct dmi_system_id disable_broken_read_transmit_power[] = {
+	{
+		 .matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,1"),
+		},
+	},
+	{
+		 .matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,2"),
+		},
+	},
+	{
+		 .matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,4"),
+		},
+	},
+	{
+		 .matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,1"),
+		},
+	},
+	{
+		 .matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "iMac20,2"),
+		},
+	},
+	{ }
+};
+
 static int btbcm_read_info(struct hci_dev *hdev)
 {
 	struct sk_buff *skb;
@@ -363,6 +398,10 @@ static int btbcm_read_info(struct hci_dev *hdev)
 	bt_dev_info(hdev, "BCM: features 0x%2.2x", skb->data[1]);
 	kfree_skb(skb);
 
+	/* Read DMI and disable broken Read LE Min/Max Tx Power */
+	if (dmi_first_match(disable_broken_read_transmit_power))
+		set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
+
 	return 0;
 }