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

From: Balakrishna Godavarthi
Date: Tue Nov 06 2018 - 08:36:31 EST


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.