Re: [PATCH AUTOSEL 5.4 133/350] Bluetooth: hci_bcm: Fix RTS handling during startup

Ondřej Jirman
2019-12-16T18:24:44Z

On Mon, Dec 16, 2019 at 02:27:50PM +0100, Greg KH wrote:
> On Mon, Dec 16, 2019 at 02:15:12PM +0100, Ondřej Jirman wrote:
> > Hi,
> >
> > On Tue, Dec 10, 2019 at 04:03:58PM -0500, Sasha Levin wrote:
> > > From: Stefan Wahren <wahrenst@gmx.net>
> > >
> > > [ Upstream commit 3347a80965b38f096b1d6f995c00c9c9e53d4b8b ]
> > >
> > > The RPi 4 uses the hardware handshake lines for CYW43455, but the chip
> > > doesn't react to HCI requests during DT probe. The reason is the inproper
> > > handling of the RTS line during startup. According to the startup
> > > signaling sequence in the CYW43455 datasheet, the hosts RTS line must
> > > be driven after BT_REG_ON and BT_HOST_WAKE.
> > >
> > > Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> > > Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
> > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > ---
> > > drivers/bluetooth/hci_bcm.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> > > index 7646636f2d183..0f73f6a686cb7 100644
> > > --- a/drivers/bluetooth/hci_bcm.c
> > > +++ b/drivers/bluetooth/hci_bcm.c
> > > @@ -445,9 +445,11 @@ static int bcm_open(struct hci_uart *hu)
> > >
> > > out:
> > > if (bcm->dev) {
> > > + hci_uart_set_flow_control(hu, true);
> > > hu->init_speed = bcm->dev->init_speed;
> > > hu->oper_speed = bcm->dev->oper_speed;
> > > err = bcm_gpio_set_power(bcm->dev, true);
> > > + hci_uart_set_flow_control(hu, false);
> > > if (err)
> > > goto err_unset_hu;
> > > }
> >
> > This causes bluetooth breakage (degraded bluetooth performance, due to failure to
> > switch to higher baudrate) for Orange Pi 3 board:
> >
> > [ 3.839134] Bluetooth: hci0: command 0xfc18 tx timeout
> > [ 11.999136] Bluetooth: hci0: BCM: failed to write update baudrate (-110)
> > [ 12.004613] Bluetooth: hci0: Failed to set baudrate
> > [ 12.123187] Bluetooth: hci0: BCM: chip id 130
> > [ 12.128398] Bluetooth: hci0: BCM: features 0x0f
> > [ 12.154686] Bluetooth: hci0: BCM4345C5
> > [ 12.157165] Bluetooth: hci0: BCM4345C5 (003.006.006) build 0000
> > [ 15.343684] Bluetooth: hci0: BCM4345C5 (003.006.006) build 0038
> >
> > I suggest not pushing this to stable.
>
> Is it being fixed in Linus's tree?

No. This patch broke it there as well, and no response yet from the author.

regards,
o.

> thanks,
>
> greg k-h