[PATCH] Bluetooth: btmtk: remove extra copy in cmd array init

[Jiajia Liu]

On Wed, May 20, 2026 at 08:55:46AM -0400, Luiz Augusto von Dentz wrote:
> Hi Jiajia,
> 
> On Tue, May 19, 2026 at 10:15 PM Jiajia Liu <liujiajia at kylinos.cn> wrote:
> >
> > In btmtk_setup_firmware_79xx, the data length indicated by wmt_params.dlen
> > in the cmd buffer is MTK_SEC_MAP_NEED_SEND_SIZE + 1. Except for the first
> > byte, the remaining length is MTK_SEC_MAP_NEED_SEND_SIZE. memcpy copied one
> > more byte to cmd + 1 than the remaining length. Align the length passed to
> > memcpy to avoid exceeding current section map.
> >
> > Signed-off-by: Jiajia Liu <liujiajia at kylinos.cn>
> > ---
> >  drivers/bluetooth/btmtk.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
> > index ea7a031000cd..53cba71cb07f 100644
> > --- a/drivers/bluetooth/btmtk.c
> > +++ b/drivers/bluetooth/btmtk.c
> > @@ -188,7 +188,7 @@ int btmtk_setup_firmware_79xx(struct hci_dev *hdev, const char *fwname,
> >                                        MTK_FW_ROM_PATCH_GD_SIZE +
> >                                        MTK_FW_ROM_PATCH_SEC_MAP_SIZE * i +
> >                                        MTK_SEC_MAP_COMMON_SIZE,
> > -                                      MTK_SEC_MAP_NEED_SEND_SIZE + 1);
> > +                                      MTK_SEC_MAP_NEED_SEND_SIZE);
> >
> >                                 wmt_params.op = BTMTK_WMT_PATCH_DWNLD;
> >                                 wmt_params.status = &status;
> > --
> > 2.53.0
> >
> 
> Have you tested this on the actual hardware? If not we need a Tested-by.

Yes, I have tested with MT7922 (0489:e0d8) on linux 7.1-rc4 applied this patch
and the following two.

Bluetooth: btmtk: accept too short WMT FUNC_CTRL events
Bluetooth: btmtk: fix urb->setup_packet leak in error paths

setup log of boot and rfkill switch:

$ dmesg | grep hci0

[    6.108240] Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20260224103448
[    8.933508] Bluetooth: hci0: Device setup in 2765295 usecs
[    8.938846] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
[   57.209143] Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20260224103448
[   57.366004] Bluetooth: hci0: Device setup in 160450 usecs
[   57.371248] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
[  203.687643] Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20260224103448
[  203.844163] Bluetooth: hci0: Device setup in 158989 usecs
[  203.849426] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.
[  214.723250] Bluetooth: hci0: HW/SW Version: 0x008a008a, Build Time: 20260224103448
[  214.879380] Bluetooth: hci0: Device setup in 155239 usecs
[  214.884644] Bluetooth: hci0: HCI Enhanced Setup Synchronous Connection command is advertised, but not supported.

> 
> -- 
> Luiz Augusto von Dentz