Re: [PATCH v6 2/2] btbcm: disable read tx power for affected Macs with the T2 Security chip
From: Orlando Chamberlain <hidden>
Date: 2021-11-30 10:28:32
Also in:
lkml, regressions, stable
On Tue, 30 Nov 2021 01:00:43 +1100 "Aditya Garg" [off-list ref] wrote:
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> Link: https://lore.kernel.org/r/4970a940-211b-25d6-edab-21a815313954@protonmail.com (local) Fixes: 7c395ea521e6 ("Bluetooth: Query LE tx power on startup") ---
It's hard to tell what the differences between versions of this patch are. This spot here after the "---" is often used for a change log (e.g. "v5->v6: Made change X and change Y"), so it would be useful to have that if you can add one in future patches. I think someone may have mentioned this earlier.
quoted hunk ↗ jump to hunk
drivers/bluetooth/btbcm.c | 40 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c index e4182acee488c5..40f7c9c5cf0a5a 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 +344,44 @@ 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; + const struct dmi_system_id;
This line seems to produce a compiler warning:
drivers/bluetooth/btbcm.c: In function ‘btbcm_read_info’:
drivers/bluetooth/btbcm.c:384:22: warning: empty declaration with type
qualifier does not redeclare tag
384 | const struct dmi_system_id;
| ^~~~~~~~~~~~~
I think Marcel mentioned this line could be removed.
The two patches make Bluetooth work on my MacBookPro16,1, with and without
that line.
Tested-by: Orlando Chamberlain <redacted>
quoted hunk ↗ jump to hunk
/* Read Verbose Config Version Info */ skb = btbcm_read_verbose_config(hdev);@@ -363,6 +399,10 @@ 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; }
-- Thanks, Orlando