Hi Calvin,
On Sat, Aug 30, 2025 at 3:32 PM Calvin Owens <calvin@xxxxxxxxxx> wrote:
>
> On Saturday 08/30 at 07:11 +0200, Paul Menzel wrote:
> > Dear Calvin,
> >
> >
> > Thank you for your patch, and addressing the regression right away.
> >
> > Am 30.08.25 um 02:50 schrieb Calvin Owens:
> > > Syzbot found a randconfig which fails after my recent patch:
> > >
> > > drivers/bluetooth/btmtksdio.c:442:33: error: array type has incomplete element type ‘struct h4_recv_pkt’
> > > 442 | static const struct h4_recv_pkt mtk_recv_pkts[] = {
> > > | ^~~~~~~~~~~~~
> > > drivers/bluetooth/btmtksdio.c:443:11: error: ‘H4_RECV_ACL’ undeclared here (not in a function)
> > > 443 | { H4_RECV_ACL, .recv = btmtksdio_recv_acl },
> > > | ^~~~~~~~~~~
> > > drivers/bluetooth/btmtksdio.c:444:11: error: ‘H4_RECV_SCO’ undeclared here (not in a function)
> > > 444 | { H4_RECV_SCO, .recv = hci_recv_frame },
> > > | ^~~~~~~~~~~
> > > drivers/bluetooth/btmtksdio.c:445:11: error: ‘H4_RECV_EVENT’ undeclared here (not in a function)
> > > 445 | { H4_RECV_EVENT, .recv = btmtksdio_recv_event },
> > >
> > > ...because we can have BT_MTKSDIO=y with BT_HCIUART_H4=n, and the
> > > definitions used here are gated on BT_HCIUART_H4 in hci_uart.h.
> >
> > The drivers below seem to be affected:
> >
> > drivers/bluetooth/bpa10x.c: { H4_RECV_EVENT, .recv =
> > hci_recv_frame },
> > drivers/bluetooth/btmtksdio.c: { H4_RECV_EVENT, .recv =
> > btmtksdio_recv_event },
> > drivers/bluetooth/btmtkuart.c: { H4_RECV_EVENT, .recv =
> > btmtkuart_recv_event },
> > drivers/bluetooth/btnxpuart.c: { H4_RECV_EVENT, .recv =
> > hci_recv_frame },
> >
> > > I think the simplest way to fix this is to remove the gate on the
> > > definitions in hci_uart.h. Since the constants are macros, there's no
> > > runtime cost to doing so, and nothing seems to rely on their absence in
> > > the BT_HCIUART_H4=n case.
> >
> > Looking at the implementation, it looks like they only work with the H4
> > protocol? So maybe, that should be denoted in the Kconfig files?
>
> Thanks for looking Paul.
>
> Yes, my fix will cause a link error with other randconfigs, which my
> 'make randconfig drivers/bluetooth/' test loop missed after I made the
> function prototype always defined, whoops.
>
> We do need the dependencies here, as you note. The btmtksdio case syzbot
> found is the odd one out because it only uses the constants, and doesn't
> call h4_recv_buf().
>
> Hopefully this gets it all:
>
> -----8<-----
> From: Calvin Owens <calvin@xxxxxxxxxx>
> Subject: [PATCH v2] Bluetooth: Fix build after header cleanup
>
> Some Kconfig dependencies are needed after my recent cleanup, since
> the core code has its own option.
>
> Since btmtksdio does not actually call h4_recv_buf(), move the
> definitions it uses outside the BT_HCIUART_H4 gate in hci_uart.h to
> avoid adding a dependency for btmtksdio.
>
> The rest I touched (bpa10x, btmtkuart, and btnxpuart) do really call
> h4_recv_buf(), so the dependency is required, add it for them.
>
> Fixes: 74bcec450eea ("Bluetooth: remove duplicate h4_recv_buf() in header")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202508300413.OnIedvRh-lkp@xxxxxxxxx/
> Signed-off-by: Calvin Owens <calvin@xxxxxxxxxx>
> ---
> drivers/bluetooth/Kconfig | 6 ++++++
> drivers/bluetooth/hci_uart.h | 8 ++++----
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
> index 4ab32abf0f48..7df69ccb6600 100644
> --- a/drivers/bluetooth/Kconfig
> +++ b/drivers/bluetooth/Kconfig
> @@ -312,7 +312,9 @@ config BT_HCIBCM4377
>
> config BT_HCIBPA10X
> tristate "HCI BPA10x USB driver"
> + depends on BT_HCIUART
> depends on USB
> + select BT_HCIUART_H4
> help
> Bluetooth HCI BPA10x USB driver.
> This driver provides support for the Digianswer BPA 100/105 Bluetooth
> @@ -437,8 +439,10 @@ config BT_MTKSDIO
>
> config BT_MTKUART
> tristate "MediaTek HCI UART driver"
> + depends on BT_HCIUART
> depends on SERIAL_DEV_BUS
> depends on USB || !BT_HCIBTUSB_MTK
> + select BT_HCIUART_H4
> select BT_MTK
> help
> MediaTek Bluetooth HCI UART driver.
> @@ -483,7 +487,9 @@ config BT_VIRTIO
>
> config BT_NXPUART
> tristate "NXP protocol support"
> + depends on BT_HCIUART
> depends on SERIAL_DEV_BUS
> + select BT_HCIUART_H4
> select CRC32
> select CRC8
> help
> diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
> index 5ea5dd80e297..cbbe79b241ce 100644
> --- a/drivers/bluetooth/hci_uart.h
> +++ b/drivers/bluetooth/hci_uart.h
> @@ -121,10 +121,6 @@ void hci_uart_set_flow_control(struct hci_uart *hu, bool enable);
> void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
> unsigned int oper_speed);
>
> -#ifdef CONFIG_BT_HCIUART_H4
> -int h4_init(void);
> -int h4_deinit(void);
> -
> struct h4_recv_pkt {
> u8 type; /* Packet type */
> u8 hlen; /* Header length */
> @@ -162,6 +158,10 @@ struct h4_recv_pkt {
> .lsize = 2, \
> .maxlen = HCI_MAX_FRAME_SIZE \
>
> +#ifdef CONFIG_BT_HCIUART_H4
> +int h4_init(void);
> +int h4_deinit(void);
> +
> struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
> const unsigned char *buffer, int count,
> const struct h4_recv_pkt *pkts, int pkts_count);
> --
> 2.47.2
Please send a v2 then otherwise this is no pickup by the likes of CI
and patchwork.
>
--
Luiz Augusto von Dentz
