Re: [PATCH v1] Bluetooth: hci_qca: Give enough time to ROME controller to bootup.

[Balakrishna Godavarthi]

Hi Stepen,

On 2019-03-07 04:03, Stephen Boyd wrote:
> Quoting Balakrishna Godavarthi (2019-03-06 08:21:13)
> > This patch enables enough time to ROME controller to bootup
> > after we bring the enable ping out of reset.
> >
> > Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
> > ---
>
> Any Fixes tag? And maybe some more explanation or background on where
> 150 ms sleep comes from would be useful. Was it determined
> experimentally or did it come from a datasheet somewhere? Does the time
> differ between boards?
[Bala]: this was observed in our stress testing and even the CHIP 
firmware team
        confirmed that BT chip required at least 150 ms to boot up.

@Rocky to confirm my statement.

> >  drivers/bluetooth/hci_qca.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> > index 237aea34b69f..1953b13511e7 100644
> > --- a/drivers/bluetooth/hci_qca.c
> > +++ b/drivers/bluetooth/hci_qca.c
> > @@ -508,6 +508,8 @@ static int qca_open(struct hci_uart *hu)
> >                 qcadev = serdev_device_get_drvdata(hu->serdev);
> >                 if (qcadev->btsoc_type != QCA_WCN3990) {
> >                         gpiod_set_value_cansleep(qcadev->bt_en, 1);
> > +                       /* Controller needs time to bootup. */
> > +                       msleep(150);
> >                 } else {
> >                         hu->init_speed = qcadev->init_speed;
> >                         hu->oper_speed = qcadev->oper_speed;

--
Regards
Balakrishna.