From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balakrishna Godavarthi Subject: Re: [PATCH v5 2/5] Bluetooth: hci_qca: Deassert RTS while baudrate change command Date: Mon, 21 Jan 2019 20:11:39 +0530 Message-ID: <24831204bab89250099ca56e7562bd16@codeaurora.org> References: <20190110143928.GE3430@localhost> <61301df80bd6a8ee0265b31b7f6a3aa1@codeaurora.org> <20190111013707.GD261387@google.com> <194b5d18ea86830b6a24939d483a964c@codeaurora.org> <20190111235633.GK261387@google.com> <20190115234628.GQ261387@google.com> <20190117160944.GV3691@localhost> <20190117172109.GU261387@google.com> <20190118094416.GB3691@localhost> <20190119003109.GD261387@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190119003109.GD261387@google.com> Sender: linux-kernel-owner@vger.kernel.org To: Matthias Kaehlcke Cc: Johan Hovold , marcel@holtmann.org, johan.hedberg@gmail.com, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org, Johan Hovold List-Id: linux-arm-msm@vger.kernel.org Hi Matthias, On 2019-01-19 06:01, Matthias Kaehlcke wrote: > On Fri, Jan 18, 2019 at 10:44:16AM +0100, Johan Hovold wrote: >> On Thu, Jan 17, 2019 at 09:21:09AM -0800, Matthias Kaehlcke wrote: >> >> > I observed that the qcom_geni_serial driver doesn't raise RTS with >> > flow control disabled. It seems we have to investigate why that's the >> > case. I agree that the driver should be platform agnostic. >> >> Sounds like a driver bug, unless the hardware is just "odd". The >> driver implementation of this looks very non-standard judging from a >> quick peek. >> >> In fact, qcom_geni_serial_get_mctrl() is currently a no-op if hardware >> flow control is not enabled: >> >> if (uart_console(uport) || !uart_cts_enabled(uport)) >> return; >> >> Perhaps dropping the !uart_cts_enabled() test is sufficient. > > Thanks for taking a look Johan, that was indeed the problem (also > in set_mctrl()). I posted a fix: > https://lore.kernel.org/patchwork/patch/1033611/ > > Balakrishna, the following (applied on top of your patch) works for me > with the UART patch above: > [Bala]: will test and update BT patch accordingly. > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index 9d5e41f159c78f..60bfdf01f72841 100644 > --- a/drivers/bluetooth/hci_qca.c > +++ b/drivers/bluetooth/hci_qca.c > @@ -1080,7 +1080,7 @@ static int qca_set_speed(struct hci_uart *hu, > enum qca_speed_type speed_type) > { > unsigned int speed, qca_baudrate; > struct qca_serdev *qcadev; > - int ret; > + int ret = 0; > > if (speed_type == QCA_INIT_SPEED) { > speed = qca_get_speed(hu, QCA_INIT_SPEED); > @@ -1097,22 +1097,27 @@ static int qca_set_speed(struct hci_uart *hu, > enum qca_speed_type speed_type) > * the old speed. > */ > qcadev = serdev_device_get_drvdata(hu->serdev); > - if (qcadev->btsoc_type == QCA_WCN3990) > + if (qcadev->btsoc_type == QCA_WCN3990) { > + hci_uart_set_flow_control(hu, true); > serdev_device_set_rts(hu->serdev, false); > + } > > qca_baudrate = qca_get_baudrate_value(speed); > bt_dev_dbg(hu->hdev, "Set UART speed to %d", speed); > ret = qca_set_baudrate(hu->hdev, qca_baudrate); > if (ret) > - return ret; > + goto out; > > host_set_baudrate(hu, speed); > > - if (qcadev->btsoc_type == QCA_WCN3990) > +out: > + if (qcadev->btsoc_type == QCA_WCN3990) { > + hci_uart_set_flow_control(hu, false); > serdev_device_set_rts(hu->serdev, true); > + } > } > > - return 0; > + return ret; > } > > static int qca_wcn3990_init(struct hci_uart *hu) -- Regards Balakrishna.