From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcel Holtmann Subject: Re: [PATCH v1 3/4] Bluetooth: hci_qca: clear HCI_QUIRK_RESET_ON_CLOSE flag Date: Wed, 14 Nov 2018 08:48:19 +0100 Message-ID: References: <20181106120528.30342-1-bgodavar@codeaurora.org> <20181106120528.30342-4-bgodavar@codeaurora.org> <462C4F58-E6E2-4B20-B074-72DDFA6D7364@holtmann.org> <170e0419929840109d349b5df5e38364@codeaurora.org> <0CE81F0B-B122-4793-817F-F0F4738C44E0@holtmann.org> <3c9684ec5fcc9f5d99be7e9b2e705514@codeaurora.org> Mime-Version: 1.0 (Mac OS X Mail 12.1 \(3445.101.1\)) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <3c9684ec5fcc9f5d99be7e9b2e705514@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Balakrishna Godavarthi Cc: Johan Hedberg , Matthias Kaehlcke , open list , linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org 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 >>>>>> --- >>>>>> 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 didn’t 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. you tell me actually. Are you using the H:4 transport or do you have an extra protocol layer / framing below it. If you do, then use your own driver, but if the transport is H:4 with vendor packets and vendor setup, then btuart.c (which is not yet upstream) should be your target. For the MTK hardware it was obvious that it was better served as a separate driver. For QCA serial it really depends on how much extra protocol you have to run. So this might be an exercise in trying QCA serial as a separate driver and then go from there. It is clear that the baggage from hci_ldisc.c etc is in the way for serdev based systems. Regards Marcel