[PATCH v9 2/2] btbcm: disable read tx power for affected Macs with the T2 Security chip
From: Aditya Garg <hidden>
Date: 2021-12-02 10:16:28
Also in:
lkml, regressions, stable
Subsystem:
bluetooth drivers, the rest · Maintainers:
Marcel Holtmann, Luiz Augusto von Dentz, Linus Torvalds
From: Aditya Garg <redacted> 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 <redacted> Reported-by: Orlando Chamberlain <redacted> Tested-by: Orlando Chamberlain <redacted> Link: https://lore.kernel.org/r/4970a940-211b-25d6-edab-21a815313954@protonmail.com (local) Fixes: 7c395ea521e6 ("Bluetooth: Query LE tx power on startup") Cc: stable@vger.kernel.org --- v7 :- Removed unused variable and added Tested-by. v8 :- No change. v9 :- Add Cc: stable@vger.kernel.org drivers/bluetooth/btbcm.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+)
diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index e4182acee488c5..07fabaa5aa2979 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>
@@ -343,6 +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; }