Messages in this thread | | | Date | Thu, 15 Nov 2018 20:04:29 +0530 | From | Balakrishna Godavarthi <> | Subject | Re: [PATCH v1 1/4] Bluetooth: hci_qca: use wait_until_sent() for power pulses |
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Hi Johan,
On 2018-11-14 20:57, Johan Hovold wrote: > On Tue, Nov 06, 2018 at 05:35:25PM +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@codeaurora.org> >> --- >> drivers/bluetooth/hci_qca.c | 22 +++++++++------------- >> 1 file changed, 9 insertions(+), 13 deletions(-) >> >> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c >> index f72ded4ec9ae..051f081d1835 100644 >> --- a/drivers/bluetooth/hci_qca.c >> +++ b/drivers/bluetooth/hci_qca.c >> @@ -1016,8 +1016,7 @@ static inline void host_set_baudrate(struct >> hci_uart *hu, unsigned int speed) >> static int qca_send_power_pulse(struct hci_dev *hdev, 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 >> @@ -1030,18 +1029,14 @@ static int qca_send_power_pulse(struct hci_dev >> *hdev, u8 cmd) >> * 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; >> - >> hci_uart_set_flow_control(hu, true); >> + ret = serdev_device_write(hu->serdev, &cmd, sizeof(cmd), 0); > > Don't you want a non-zero timeout here? Otherwise you might as well > call > serdev_device_write() directly. >
[Bala]: we need an in definite timeout for these commands. will use HCI_UART_TX_WAKEUP.
> Also have you made sure that serdev_device_write_wakeup() is called in > the drivers write-wakeup callback as serdev_device_write() requires? > > See this series in case what you really wanted was to wait indefinitely > (you can use MAX_SCHEDULE_TIMEOUT): > > https://lkml.kernel.org/r/<20181114150904.19653-1-johan@kernel.org> >
[Bala]: thanks for pointers. from https://lore.kernel.org/patchwork/patch/1012358/ it was clear to me that i need call below functions in order to wait until full data is sent.
serdev_device_write_wakeup() serdev_device_write() serdev_device_wait_until_sent()
correct me whether my understanding is correct.
>> + if (ret < 0) { >> + bt_dev_err(hdev, "failed to send power pulse %02x to SoC", 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); >> @@ -1283,7 +1278,8 @@ static void qca_power_shutdown(struct hci_uart >> *hu) >> >> host_set_baudrate(hu, 2400); >> hci_uart_set_flow_control(hu, true); >> - serdev_device_write_buf(serdev, &cmd, sizeof(cmd)); >> + serdev_device_write(serdev, &cmd, sizeof(cmd), 0); > > Same here. > >> + serdev_device_wait_until_sent(serdev, 0); >> hci_uart_set_flow_control(hu, false); >> qca_power_setup(hu, false); >> } > > Johan
-- Regards Balakrishna.
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