Re: [PATCH v1 3/4] Bluetooth: hci_qca: clear HCI_QUIRK_RESET_ON_CLOSE flag

[Balakrishna Godavarthi]

Hi Marcel,

On 2018-11-06 18:44, Balakrishna Godavarthi wrote:
> Hi Marcel,
>
> On 2018-11-06 18:32, Marcel Holtmann wrote:
> > Hi Balakrishna,
> >
> > > > > During hci down we are sending reset command to chip, which
> > > > > is not required for wcn3990, as hdev->shutdown() will turn off the
> > > > > regulators.
> > > > > Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
> > > > > ---
> > > > > drivers/bluetooth/hci_qca.c | 1 +
> > > > > 1 file changed, 1 insertion(+)
> > > > > diff --git a/drivers/bluetooth/hci_qca.c 
> > > > > b/drivers/bluetooth/hci_qca.c
> > > > > index 8301663f0004..97b57e0f4725 100644
> > > > > --- a/drivers/bluetooth/hci_qca.c
> > > > > +++ b/drivers/bluetooth/hci_qca.c
> > > > > @@ -1190,6 +1190,7 @@ static int qca_setup(struct hci_uart *hu)
> > > > > 		 */
> > > > > 		set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
> > > > > 		set_bit(HCI_QUIRK_USE_BDADDR_PROPERTY, &hdev->quirks);
> > > > > +		clear_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
> > > > > 		hu->hdev->shutdown = qca_power_off;
> > > > > 		ret = qca_wcn3990_init(hu);
> > > > > 		if (ret)
> > > > I am pretty certain that you didnât want this quirk:
> > > >        /* When this quirk is set, the HCI Reset command is send when
> > > >         * closing the transport instead of when opening it.
> > > > This quirk is for Bluetooth 1.0b devices where the HCI_Reset 
> > > > behavior
> > > > was not clear or for devices that actually misbehave with the 
> > > > initial
> > > > HCI_Reset.
> > > > In addition, you commit message is totally misleading. That is not
> > > > what is happening with this quirk.
> > > > Regards
> > > > Marcel
> > >
> > > My intention was reset command is not required when we do an hci 
> > > down.
> > > this is because of hdev->shutdown will turn off the regulators.
> > > It is like turning off the chip. sending reset command after turning 
> > > off the chip is not required.
> > >
> > > I understand the usage of the quirk, will update the commit text.
> >
> > you are papering over the issue. Actually
> > hci_serdev.c:hci_uart_register_device() is the culprit with the legacy
> > code copied over from hci_ldisc.c:hci_uart_register_dev(). I think
> > there is no point doing all this legacy line discipline quirk handling
> > until it is really needed. The serdev drivers are all for recent
> > hardware.
> >
> > That said, having moved over to a btuart.c approach and killed the
> > whole hci_serdev.c thing would have been a lot better here. You will
> > keep running in weird situations where 18 year old code keeps
> > surprising you.
>
> [Bala]: even i feel the same. they are lot such kind of HACK's we need
> to do with current arch.
>         when can we expect btuart.c merged to bt-next. i think having
> btuart will helps us to have the control of
>         vendor porto's call's like in btusb.c
>
> > Regards
> >
> > Marcel

I need some clarification, do you expect some thing like this 
https://github.com/torvalds/linux/blob/master/drivers/bluetooth/btmtkuart.c 
for Qualcomm BT chip too.
it looks it is completely avoided hci_serdev.c interface.

--
Regards
Balakrishna.