[PATCH v2 2/6] btbcm: disable read tx power for MacBook Pro 16,1 (16 inch, 2019)

[Aditya Garg]

From: Aditya Garg <gargaditya08@xxxxxxxx>

Bluetooth on Apple MacBook Pro 16,1 is unable to start due to LE Min/Max Tx Power being queried on 
startup. Add a DMI based quirk so that it is disabled.

v2: Wrap the changeling at 72 columns and remove tested by.

Signed-off-by: Aditya Garg <gargaditya08@xxxxxxxx>
---
 drivers/bluetooth/btbcm.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index e4182acee488c5..c1b0ca63880a68 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/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>
@@ -343,9 +344,23 @@ 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[] = {
+	{
+		/* Match for Apple MacBook Pro 16,1 which needs
+		 * Read LE Min/Max Tx Power to be disabled.
+		 */
+		 .matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,1"),
+		},
+	},
+	{ }
+};
+
 static int btbcm_read_info(struct hci_dev *hdev)
 {
 	struct sk_buff *skb;
+	const struct dmi_system_id *dmi_id;
 
 	/* Read Verbose Config Version Info */
 	skb = btbcm_read_verbose_config(hdev);
@@ -362,6 +377,11 @@ 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 */
+	dmi_id = dmi_first_match(disable_broken_read_transmit_power);
+	if (dmi_id)
+		set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
 
 	return 0;
 }