Re: [PATCH v1] Bluetooth: btmtk: add event filter to filter specific event

["Chris Lu (陸稚泓)" <Chris.Lu@mediatek.com>]

Dear Paul,


On Tue, 2026-04-07 at 09:14 +0200, Paul Menzel wrote:
> 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Dear Chris,
> 
> 
> Thank you for the patch.
> 
> Am 07.04.26 um 08:47 schrieb Chris Lu:
> > Due to some Bluetooth hosts have mechanism to detect invalid
> > events,
> > causing abnormal behavior.
> 
> Sorry, this description is much too short and general. Please
> elaborate,
> and document details.
> 
> > Add a event filter to prevent debugging events from being sent to
> > host.
> 
> a*n*
> 
> What are debugging events, and how can they be detected?

Thanks for your suggestion.
I'll submit v2 to revise the commit message to avoid using vague
descriptions.

> 
> > Signed-off-by: Chris Lu <chris.lu@mediatek.com>
> 
> Should there be a Fixes: tag, so it gets backported?

No, it's not an issue derived from previous driver changes.
> 
> > ---
> >   drivers/bluetooth/btmtk.c | 22 ++++++++++++++++++++++
> >   drivers/bluetooth/btmtk.h |  7 +++++++
> >   drivers/bluetooth/btusb.c |  2 ++
> >   3 files changed, 31 insertions(+)
> > 
> > diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
> > index 55516b4602db..302d6ddf9062 100644
> > --- a/drivers/bluetooth/btmtk.c
> > +++ b/drivers/bluetooth/btmtk.c
> > @@ -1503,6 +1503,28 @@ int btmtk_usb_shutdown(struct hci_dev *hdev)
> >       return 0;
> >   }
> >   EXPORT_SYMBOL_GPL(btmtk_usb_shutdown);
> > +
> > +int btmtk_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
> > +{
> > +     struct hci_event_hdr *hdr = (void *)skb->data;
> > +
> > +     if (hdr->evt == HCI_EV_CMD_COMPLETE) {
> > +             struct hci_ev_cmd_complete *ec;
> > +             u16 opcode;
> > +
> > +             ec = (void *)(skb->data + HCI_EVENT_HDR_SIZE);
> > +             opcode = __le16_to_cpu(ec->opcode);
> > +
> > +             /* Filter vendor opcode */
> > +             if (opcode == 0xfc5d) {
> > +                     kfree_skb(skb);
> > +                     return 0;
> > +             }
> > +     }
> > +
> > +     return hci_recv_frame(hdev, skb);
> > +}
> > +EXPORT_SYMBOL_GPL(btmtk_recv_event);
> >   #endif
> > 
> >   MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
> > diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h
> > index adaf385626ee..08b73927c8f3 100644
> > --- a/drivers/bluetooth/btmtk.h
> > +++ b/drivers/bluetooth/btmtk.h
> > @@ -218,6 +218,8 @@ int btmtk_usb_suspend(struct hci_dev *hdev);
> >   int btmtk_usb_setup(struct hci_dev *hdev);
> > 
> >   int btmtk_usb_shutdown(struct hci_dev *hdev);
> > +
> > +int btmtk_recv_event(struct hci_dev *hdev, struct sk_buff *skb);
> >   #else
> > 
> >   static inline int btmtk_set_bdaddr(struct hci_dev *hdev,
> > @@ -296,4 +298,9 @@ static inline int btmtk_usb_shutdown(struct
> > hci_dev *hdev)
> >   {
> >       return -EOPNOTSUPP;
> >   }
> > +
> > +static inline int btmtk_recv_event(struct hci_dev *hdev, struct
> > sk_buff *skb)
> > +{
> > +     return -EOPNOTSUPP;
> > +}
> >   #endif
> > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> > index f9d515ee9124..daf8a387e660 100644
> > --- a/drivers/bluetooth/btusb.c
> > +++ b/drivers/bluetooth/btusb.c
> > @@ -4150,6 +4150,8 @@ static int btusb_probe(struct usb_interface
> > *intf,
> >       } else if (id->driver_info & BTUSB_MEDIATEK) {
> >               /* Allocate extra space for Mediatek device */
> >               priv_size += sizeof(struct btmtk_data);
> > +
> > +             data->recv_event = btmtk_recv_event;
> >       }
> > 
> >       data->recv_acl = hci_recv_frame;
> 
> 
> Kind regards,
> 
> Paul

Thanks,
Chris Lu