Hi Marcel, hi Johan, Am 06.10.19 um 17:28 schrieb Stefan Wahren: > 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@xxxxxxx> > --- > 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 7646636..0f73f6a 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; > } > -- > 2.7.4 would be nice to get some feedback about this. Regards Stefan