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

From: Aditya Garg
Date: Mon Nov 29 2021 - 02:29:44 EST


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.

Signed-off-by: Aditya Garg <gargaditya08@xxxxxxxx>
Tested-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;
}