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

From: Aditya Garg
Date: Mon Nov 29 2021 - 03:13:24 EST




> On 29-Nov-2021, at 1:38 PM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote:
>
> Hi Aditya,
>
>> 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.
>
> list all the MacBooks that you found problematic right now. We add the
> initial as a large batch instead of all individual.
>
>>
>> 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.
>> + */
>
> Actually leave the comment out. You are not adding any value that isn’t
> already in the variable name or the DMI. It is just repeating the obvious.
Alright, I prepare the patches into a single one
>
>> + .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);
>
> if (dmi_first_match(..))
> set_bit(.., &hdev->quirks);
>
> There is really no need to have a variable for this.
Fine, Ill correct this
>
> Regards
>
> Marcel
>