Re: [PATCH v9 2/3] Bluetooth: hci_qca: Deassert RTS while baudrate change command
Hi Matthias, On 2019-01-25 05:42, Matthias Kaehlcke wrote: Hi Balakrishna, On Thu, Jan 24, 2019 at 05:38:07PM +0530, Balakrishna Godavarthi wrote: This patch will help to stop frame reassembly errors while changing the baudrate. This is because host send a change baudrate request command to the chip with 115200 bps, Whereas chip will change their UART clocks to the enable for new baudrate and sends the response for the change request command with newer baudrate, On host side we are still operating in 115200 bps which results of reading garbage data. Here we are pulling RTS line, so that chip we will wait to send data to host until host change its baudrate. Signed-off-by: Balakrishna Godavarthi Tested-by: Matthias Kaehlcke Reviewed-by: Matthias Kaehlcke --- Changes in v9: * disabled flow control while setting the baudrate of HOST and chip. --- drivers/bluetooth/hci_qca.c | 24 +--- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index c08f4d105e73..6b5bcd44e24c 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -964,7 +964,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) struct hci_uart *hu = hci_get_drvdata(hdev); struct qca_data *qca = hu->priv; struct sk_buff *skb; - struct qca_serdev *qcadev; u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 }; if (baudrate > QCA_BAUDRATE_320) @@ -978,13 +977,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) return -ENOMEM; } - /* Disabling hardware flow control is mandatory while -* sending change baudrate request to wcn3990 SoC. -*/ - qcadev = serdev_device_get_drvdata(hu->serdev); - if (qcadev->btsoc_type == QCA_WCN3990) - hci_uart_set_flow_control(hu, true); - /* Assign commands to change baudrate and packet type. */ skb_put_data(skb, cmd, sizeof(cmd)); hci_skb_pkt_type(skb) = HCI_COMMAND_PKT; @@ -1000,9 +992,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS)); set_current_state(TASK_RUNNING); - if (qcadev->btsoc_type == QCA_WCN3990) - hci_uart_set_flow_control(hu, false); - return 0; } @@ -1089,6 +1078,7 @@ static int qca_check_speeds(struct hci_uart *hu) 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; if (speed_type == QCA_INIT_SPEED) { @@ -1100,6 +1090,15 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) if (!speed) return 0; + /* Deassert RTS while changing the baudrate of chip and host. +* This will prevent chip from transmitting its response with +* the new baudrate while the host port is still operating at +* the old speed. +*/ It is not necessarily evident which action deasserts RTS, I suggest to rephrase it to something like: "Disable flow control for wcn3990 to deassert RTS while ... " [Bala]: will update. + qcadev = serdev_device_get_drvdata(hu->serdev); + if (qcadev->btsoc_type == QCA_WCN3990) + hci_uart_set_flow_control(hu, true); + 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); flow control should be re-enabled in the error path. Cheers Matthias [Bala; will update. -- Regards Balakrishna.
Re: [PATCH v9 2/3] Bluetooth: hci_qca: Deassert RTS while baudrate change command
Hi Balakrishna, On Thu, Jan 24, 2019 at 05:38:07PM +0530, Balakrishna Godavarthi wrote: > This patch will help to stop frame reassembly errors while changing > the baudrate. This is because host send a change baudrate request > command to the chip with 115200 bps, Whereas chip will change their > UART clocks to the enable for new baudrate and sends the response > for the change request command with newer baudrate, On host side > we are still operating in 115200 bps which results of reading garbage > data. Here we are pulling RTS line, so that chip we will wait to send data > to host until host change its baudrate. > > Signed-off-by: Balakrishna Godavarthi > Tested-by: Matthias Kaehlcke > Reviewed-by: Matthias Kaehlcke > --- > Changes in v9: > * disabled flow control while setting the baudrate of HOST and chip. > --- > drivers/bluetooth/hci_qca.c | 24 +--- > 1 file changed, 13 insertions(+), 11 deletions(-) > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index c08f4d105e73..6b5bcd44e24c 100644 > --- a/drivers/bluetooth/hci_qca.c > +++ b/drivers/bluetooth/hci_qca.c > @@ -964,7 +964,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t > baudrate) > struct hci_uart *hu = hci_get_drvdata(hdev); > struct qca_data *qca = hu->priv; > struct sk_buff *skb; > - struct qca_serdev *qcadev; > u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 }; > > if (baudrate > QCA_BAUDRATE_320) > @@ -978,13 +977,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, > uint8_t baudrate) > return -ENOMEM; > } > > - /* Disabling hardware flow control is mandatory while > - * sending change baudrate request to wcn3990 SoC. > - */ > - qcadev = serdev_device_get_drvdata(hu->serdev); > - if (qcadev->btsoc_type == QCA_WCN3990) > - hci_uart_set_flow_control(hu, true); > - > /* Assign commands to change baudrate and packet type. */ > skb_put_data(skb, cmd, sizeof(cmd)); > hci_skb_pkt_type(skb) = HCI_COMMAND_PKT; > @@ -1000,9 +992,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, > uint8_t baudrate) > schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS)); > set_current_state(TASK_RUNNING); > > - if (qcadev->btsoc_type == QCA_WCN3990) > - hci_uart_set_flow_control(hu, false); > - > return 0; > } > > @@ -1089,6 +1078,7 @@ static int qca_check_speeds(struct hci_uart *hu) > 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; > > if (speed_type == QCA_INIT_SPEED) { > @@ -1100,6 +1090,15 @@ static int qca_set_speed(struct hci_uart *hu, enum > qca_speed_type speed_type) > if (!speed) > return 0; > > + /* Deassert RTS while changing the baudrate of chip and host. > + * This will prevent chip from transmitting its response with > + * the new baudrate while the host port is still operating at > + * the old speed. > + */ It is not necessarily evident which action deasserts RTS, I suggest to rephrase it to something like: "Disable flow control for wcn3990 to deassert RTS while ... " > + qcadev = serdev_device_get_drvdata(hu->serdev); > + if (qcadev->btsoc_type == QCA_WCN3990) > + hci_uart_set_flow_control(hu, true); > + > 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); flow control should be re-enabled in the error path. Cheers Matthias
[PATCH v9 2/3] Bluetooth: hci_qca: Deassert RTS while baudrate change command
This patch will help to stop frame reassembly errors while changing the baudrate. This is because host send a change baudrate request command to the chip with 115200 bps, Whereas chip will change their UART clocks to the enable for new baudrate and sends the response for the change request command with newer baudrate, On host side we are still operating in 115200 bps which results of reading garbage data. Here we are pulling RTS line, so that chip we will wait to send data to host until host change its baudrate. Signed-off-by: Balakrishna Godavarthi Tested-by: Matthias Kaehlcke Reviewed-by: Matthias Kaehlcke --- Changes in v9: * disabled flow control while setting the baudrate of HOST and chip. --- drivers/bluetooth/hci_qca.c | 24 +--- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index c08f4d105e73..6b5bcd44e24c 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -964,7 +964,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) struct hci_uart *hu = hci_get_drvdata(hdev); struct qca_data *qca = hu->priv; struct sk_buff *skb; - struct qca_serdev *qcadev; u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 }; if (baudrate > QCA_BAUDRATE_320) @@ -978,13 +977,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) return -ENOMEM; } - /* Disabling hardware flow control is mandatory while -* sending change baudrate request to wcn3990 SoC. -*/ - qcadev = serdev_device_get_drvdata(hu->serdev); - if (qcadev->btsoc_type == QCA_WCN3990) - hci_uart_set_flow_control(hu, true); - /* Assign commands to change baudrate and packet type. */ skb_put_data(skb, cmd, sizeof(cmd)); hci_skb_pkt_type(skb) = HCI_COMMAND_PKT; @@ -1000,9 +992,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS)); set_current_state(TASK_RUNNING); - if (qcadev->btsoc_type == QCA_WCN3990) - hci_uart_set_flow_control(hu, false); - return 0; } @@ -1089,6 +1078,7 @@ static int qca_check_speeds(struct hci_uart *hu) 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; if (speed_type == QCA_INIT_SPEED) { @@ -1100,6 +1090,15 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) if (!speed) return 0; + /* Deassert RTS while changing the baudrate of chip and host. +* This will prevent chip from transmitting its response with +* the new baudrate while the host port is still operating at +* the old speed. +*/ + qcadev = serdev_device_get_drvdata(hu->serdev); + if (qcadev->btsoc_type == QCA_WCN3990) + hci_uart_set_flow_control(hu, true); + 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); @@ -1107,6 +1106,9 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) return ret; host_set_baudrate(hu, speed); + + if (qcadev->btsoc_type == QCA_WCN3990) + hci_uart_set_flow_control(hu, false); } return 0; -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project