lkml.org 
[lkml]   [2021]   [Nov]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCHv2] Bluetooth: quirk disabling LE Read Transmit Power
On Sat, Nov 06, 2021 at 09:41:28AM +0000, Aditya Garg wrote:
>
>
> > On 06-Nov-2021, at 3:17 AM, Luiz Augusto von Dentz <luiz.dentz@gmail.com> wrote:
> >
> > Hi Orlando,
> >
> > On Fri, Oct 1, 2021 at 1:56 AM Orlando Chamberlain
> > <redecorating@protonmail.com> wrote:
> >>
> >> The LE Read Transmit Power command is Advertised on some Broadcom
> >> controlers, but not supported. Using this command breaks Bluetooth
> >> on the MacBookPro16,1 and iMac20,1. Added a quirk disabling LE Read
> >> Transmit Power for these devices, based off their common chip id 150.
> >>
> >> Link: https://lore.kernel.org/r/4970a940-211b-25d6-edab-21a815313954@protonmail.com
> >> Signed-off-by: Orlando Chamberlain <redecorating@protonmail.com>
> >> ---
> >> v1->v2: Clarified quirk description
> >>
> >> drivers/bluetooth/btbcm.c | 4 ++++
> >> include/net/bluetooth/hci.h | 11 +++++++++++
> >> net/bluetooth/hci_core.c | 3 ++-
> >> 3 files changed, 17 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..6da9bd6b7259 100644
> >> --- a/include/net/bluetooth/hci.h
> >> +++ b/include/net/bluetooth/hci.h
> >> @@ -246,6 +246,17 @@ enum {
> >> * HCI after resume.
> >> */
> >> HCI_QUIRK_NO_SUSPEND_NOTIFIER,
> >> +
> >> + /* When this quirk is set, LE Read Transmit Power is disabled.
> >> + * This is mainly due to the fact that the HCI LE Read Transmit
> >> + * Power command is advertised, but not supported; these
> >> + * controllers often reply with unknown command and need a hard
> >> + * reset.
> >> + *
> >> + * 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
> >
> > Nowadays it is possible to treat errors such like this on a per
> > command basis (assuming it is not essential for the init sequence):
> >
> > diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> > index 979da5179ff4..f244f42cc609 100644
> > --- a/include/net/bluetooth/hci.h
> > +++ b/include/net/bluetooth/hci.h
> > @@ -551,6 +551,7 @@ enum {
> > #define HCI_LK_AUTH_COMBINATION_P256 0x08
> >
> > /* ---- HCI Error Codes ---- */
> > +#define HCI_ERROR_UNKNOWN_CMD 0x01
> > #define HCI_ERROR_UNKNOWN_CONN_ID 0x02
> > #define HCI_ERROR_AUTH_FAILURE 0x05
> > #define HCI_ERROR_PIN_OR_KEY_MISSING 0x06
> > diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
> This diff cannot be applied to stable 5.15. Could you provide a patch capable of being applied to stable.

That is not needed until a patch is in Linus's tree. Why do you need it
earlier?

thanks,

greg k-h

\
 
 \ /
  Last update: 2021-11-06 12:50    [W:0.126 / U:2.264 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site