On Fri, Dec 28, 2018 at 05:18:16PM +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 <bgodavar@xxxxxxxxxxxxxx>
> ---
> 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 | 43 ++++++++++++++++---------------------
> 1 file changed, 18 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index f036c8f98ea3..2aab34b3e696 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1013,11 +1013,9 @@ 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;
>
> /* These power pulses are single byte command which are sent
> * at required baudrate to wcn3990. On wcn3990, we have an external
> @@ -1029,22 +1027,23 @@ 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, 0);
>
> - /* Wait for 100 uS for SoC to settle down */
> - usleep_range(100, 200);
> + /* Wait of 5ms is required for assuring to send the byte on the Tx
> + * line and also for the controller to settle down for the received
> + * byte.
> + */
> + usleep_range(5000, 6000);
We could be more flexible with the range, e.g. 5 to 10 ms, but it's
also fine as is.
> hci_uart_set_flow_control(hu, false);
>
> return 0;
> @@ -1116,7 +1115,6 @@ 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 +1137,12 @@ 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 +1272,8 @@ 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);
> }
>
Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
