From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balakrishna Godavarthi Subject: Re: [PATCH v9 1/3] Bluetooth: hci_qca: use wait_until_sent() for power pulses Date: Mon, 28 Jan 2019 19:19:56 +0530 Message-ID: <0fac93a13ee445569659075cf467ad4d@codeaurora.org> References: <20190124120808.8275-1-bgodavar@codeaurora.org> <20190124120808.8275-2-bgodavar@codeaurora.org> <20190125011412.GE81583@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190125011412.GE81583@google.com> Sender: linux-kernel-owner@vger.kernel.org To: Matthias Kaehlcke Cc: marcel@holtmann.org, johan.hedberg@gmail.com, johan@kernel.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org Hi Matthias, On 2019-01-25 06:44, Matthias Kaehlcke wrote: > On Thu, Jan 24, 2019 at 05:38:06PM +0530, Balakrishna Godavarthi wrote: >> wcn3990 requires a power pulse to turn ON/OFF along with >> regulators. Sometimes we are observing the power pulses are sent >> out with some time delay, due to queuing these commands. This is >> causing synchronization issues with chip, which intern delay the >> chip setup or may end up with communication issues. >> >> Signed-off-by: Balakrishna Godavarthi >> --- >> Changes in v9: >> * Reverted to 100us sleep. >> * used inline call msecs_to_jiffies() >> >> Changes in v8: >> * Updated 1 second timeout instead of indefinite wait. >> >> Changes in v7: >> * updated the wait time to 5 ms after sending power pulses. >> >> Changes in v6: >> * added serdev_device_write_flush() in qca_send_power_pulse >> instead during the power off pulse. >> >> Changes in v5: >> * added serdev_device_write_flush() in qca_power_off(). >> --- >> drivers/bluetooth/hci_qca.c | 40 >> +++++++++++++++---------------------- >> 1 file changed, 16 insertions(+), 24 deletions(-) >> >> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c >> index f036c8f98ea3..c08f4d105e73 100644 >> --- a/drivers/bluetooth/hci_qca.c >> +++ b/drivers/bluetooth/hci_qca.c >> @@ -60,6 +60,7 @@ >> #define IBS_WAKE_RETRANS_TIMEOUT_MS 100 >> #define IBS_TX_IDLE_TIMEOUT_MS 2000 >> #define BAUDRATE_SETTLE_TIMEOUT_MS 300 >> +#define POWER_PULSE_TRANS_TIMEOUT_MS 1000 > > I still doubt that this mega-timeout of 1s is needed, but it shouldn't > do any harm either, so whatever ... > [Bala]: for now let us have it. we can improve it in the improvement patch based on the results. >> /* susclk rate */ >> #define SUSCLK_RATE_32KHZ 32768 >> @@ -1013,11 +1014,10 @@ static inline void host_set_baudrate(struct >> hci_uart *hu, unsigned int speed) >> hci_uart_set_baudrate(hu, speed); >> } >> >> -static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd) >> +static int qca_send_power_pulse(struct hci_uart *hu, u8 cmd) >> { >> - struct hci_uart *hu = hci_get_drvdata(hdev); >> - struct qca_data *qca = hu->priv; >> - struct sk_buff *skb; >> + int ret; >> + int timeout = msecs_to_jiffies(POWER_PULSE_TRANS_TIMEOUT_MS); >> >> /* These power pulses are single byte command which are sent >> * at required baudrate to wcn3990. On wcn3990, we have an external >> @@ -1029,21 +1029,19 @@ static int qca_send_power_pulse(struct hci_dev >> *hdev, u8 cmd) >> * save power. Disabling hardware flow control is mandatory while >> * sending power pulses to SoC. >> */ >> - bt_dev_dbg(hdev, "sending power pulse %02x to SoC", cmd); >> - >> - skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL); >> - if (!skb) >> - return -ENOMEM; >> + bt_dev_dbg(hu->hdev, "sending power pulse %02x to controller", cmd); >> >> + serdev_device_write_flush(hu->serdev); >> hci_uart_set_flow_control(hu, true); >> + ret = serdev_device_write_buf(hu->serdev, &cmd, sizeof(cmd)); >> + if (ret < 0) { >> + bt_dev_err(hu->hdev, "failed to send power pulse %02x", cmd); >> + return ret; >> + } >> >> - skb_put_u8(skb, cmd); >> - hci_skb_pkt_type(skb) = HCI_COMMAND_PKT; >> - >> - skb_queue_tail(&qca->txq, skb); >> - hci_uart_tx_wakeup(hu); >> + serdev_device_wait_until_sent(hu->serdev, timeout); >> >> - /* Wait for 100 uS for SoC to settle down */ >> + /* Wait for 100 uS for SoC to settle down for the received byte. */ > > I don't think 'for the received byte' adds much value here. If you > respin anyway I'd suggest to leave the comment as is. > [Bala]: will update. >> usleep_range(100, 200); >> hci_uart_set_flow_control(hu, false); >> >> @@ -1116,7 +1114,6 @@ static int qca_set_speed(struct hci_uart *hu, >> enum qca_speed_type speed_type) >> >> static int qca_wcn3990_init(struct hci_uart *hu) >> { >> - struct hci_dev *hdev = hu->hdev; >> struct qca_serdev *qcadev; >> int ret; >> >> @@ -1139,12 +1136,12 @@ static int qca_wcn3990_init(struct hci_uart >> *hu) >> >> /* Forcefully enable wcn3990 to enter in to boot mode. */ >> host_set_baudrate(hu, 2400); >> - ret = qca_send_power_pulse(hdev, QCA_WCN3990_POWEROFF_PULSE); >> + ret = qca_send_power_pulse(hu, QCA_WCN3990_POWEROFF_PULSE); >> if (ret) >> return ret; >> >> qca_set_speed(hu, QCA_INIT_SPEED); >> - ret = qca_send_power_pulse(hdev, QCA_WCN3990_POWERON_PULSE); >> + ret = qca_send_power_pulse(hu, QCA_WCN3990_POWERON_PULSE); >> if (ret) >> return ret; >> >> @@ -1274,13 +1271,8 @@ static const struct qca_vreg_data qca_soc_data >> = { >> >> static void qca_power_shutdown(struct hci_uart *hu) >> { >> - struct serdev_device *serdev = hu->serdev; >> - unsigned char cmd = QCA_WCN3990_POWEROFF_PULSE; >> - >> host_set_baudrate(hu, 2400); >> - hci_uart_set_flow_control(hu, true); >> - serdev_device_write_buf(serdev, &cmd, sizeof(cmd)); >> - hci_uart_set_flow_control(hu, false); >> + qca_send_power_pulse(hu, QCA_WCN3990_POWEROFF_PULSE); >> qca_power_setup(hu, false); >> } >> > > Looks good to me besides possible minor improvements: > > Reviewed-by: Matthias Kaehlcke -- Regards Balakrishna.