Commit 7c395ea521e6 made Bluetooth stop working on the MacBookPro16,1. I believe this also affected the iMac20,1. The patch below introduces a quirk disabling Read LE Min/Max Tx Power for affected computers, based off the brcm chip id 150. I think there are a couple of issues with this patch that I don't have the knowledge to resolve: 1. I don't know how accurate the description of the quirk is, I based it off the commit message of 7c395ea521e6m, however I don't understand much about how Bluetooth works. Other Bluetooth quirks also have explanations as to why they are needed, I don't know why this quirk is needed (is it that these chips incorrectly say they support read le minmax tx power? I just don't know). 2. It may be a bug in the min max le tx power code that could be fixed instead of disabling it for the affected devices. I haven't had much success in figuring out exactly why reading le minmax tx power stops Bluetooth from working. I have noticed that these lines are not present in dmesg when Bluetooth is not working due to this issue: Bluetooth: RFCOMM TTY layer initialized Bluetooth: RFCOMM socket layer initialized Bluetooth: RFCOMM ver 1.11 I have also added some logging around the changes in 7c395ea521e6, the two patches (one with bt working one without) I tried and their associated dmesgs are here https://gist.github.com/Redecorating/8330bb58a7cb8730be3956058ba4599f Regards, Orlando Chamberlain --- drivers/bluetooth/btbcm.c | 4 ++++ include/net/bluetooth/hci.h | 9 +++++++++ net/bluetooth/hci_core.c | 3 ++- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c index e4182acee488..4ecc50d93107 100644 --- a/drivers/bluetooth/btbcm.c +++ b/drivers/bluetooth/btbcm.c @@ -353,6 +353,10 @@ static int btbcm_read_info(struct hci_dev *hdev) return PTR_ERR(skb); bt_dev_info(hdev, "BCM: chip id %u", skb->data[1]); + + if (skb->data[1] == 150) + set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks); + kfree_skb(skb); /* Read Controller Features */ diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h index b80415011dcd..9ce46cb8564d 100644 --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -246,6 +246,15 @@ enum { * HCI after resume. */ HCI_QUIRK_NO_SUSPEND_NOTIFIER, + + /* + * When this quirk is set, LE tx power is not queried on startup + * and the min/max tx power values default to HCI_TX_POWER_INVALID. + * + * This quirk can be set before hci_register_dev is called or + * during the hdev->setup vendor callback. + */ + HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, }; /* HCI device flags */ diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 8a47a3017d61..9a23fe7c8d67 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -742,7 +742,8 @@ static int hci_init3_req(struct hci_request *req, unsigned long opt) hci_req_add(req, HCI_OP_LE_READ_ADV_TX_POWER, 0, NULL); } - if (hdev->commands[38] & 0x80) { + if (hdev->commands[38] & 0x80 && + !test_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks)) { /* Read LE Min/Max Tx Power*/ hci_req_add(req, HCI_OP_LE_READ_TRANSMIT_POWER, 0, NULL); -- 2.33.0
