| Message ID | 20181217141330.6294-2-bgodavar@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | Bug fixes for Qualcomm BT chip wcn3990 | expand |
On Mon, Dec 17, 2018 at 07:43:26PM +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> > --- > v4: > * used serdev_device_write_buf() instead of serdev_device_write() > > v3: > * no change. > v2: > * Updated function qca_send_power_pulse() > * addressed reviewer comments. > > v1: > * initial patch > > --- > drivers/bluetooth/hci_qca.c | 37 +++++++++++++------------------------ > 1 file changed, 13 insertions(+), 24 deletions(-) > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index f036c8f98ea3..d8bc77c8c9b9 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 > @@ -1029,19 +1027,16 @@ 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 SoC", cmd); > 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 to SoC", > + cmd); > + return ret; > + } As I mentioned earlier, serdev_device_write_buf() can buffer less than sizeof(cmd) bytes if the tty driver's write buffer is full (and return the number of bytes buffered). How you want to deal with that is up to you and the bluetooth maintainers, but I think you want to at least log it even if you choose to ignore it. Johan
Hi Johan, On 2018-12-18 14:43, Johan Hovold wrote: > On Mon, Dec 17, 2018 at 07:43:26PM +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> >> --- >> v4: >> * used serdev_device_write_buf() instead of serdev_device_write() >> >> v3: >> * no change. >> v2: >> * Updated function qca_send_power_pulse() >> * addressed reviewer comments. >> >> v1: >> * initial patch >> >> --- >> drivers/bluetooth/hci_qca.c | 37 >> +++++++++++++------------------------ >> 1 file changed, 13 insertions(+), 24 deletions(-) >> >> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c >> index f036c8f98ea3..d8bc77c8c9b9 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 >> @@ -1029,19 +1027,16 @@ 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 SoC", cmd); >> 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 to SoC", >> + cmd); >> + return ret; >> + } > > As I mentioned earlier, serdev_device_write_buf() can buffer less than > sizeof(cmd) bytes if the tty driver's write buffer is full (and return > the number of bytes buffered). > > How you want to deal with that is up to you and the bluetooth > maintainers, but I think you want to at least log it even if you choose > to ignore it. > > Johan [Bala]: thanks for reminding me for buffer size. we use the qca_send_power_pulse() where we use serdev_write_buf() to send a single byte commands to the chip during power ON or power OFF i.e. as soon as we open port or before close. during power on: ideally open port can guarantee me to the have tty buffer empty as we didn't queued any data. let us assume that if the buffer is full(), serdev_device_write_buf() will return -1 (as buffer is full) anyways i have check for return status to log the write_buf failure. during power off: yes here we may face an issue as already we have some data queued in the buffer. i.e. due to previous transactions. I think we can achieve this by calling serdev_device_write_flush() and then calling serdev_device_write_buf().
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index f036c8f98ea3..d8bc77c8c9b9 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 @@ -1029,19 +1027,16 @@ 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 SoC", cmd); 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 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); @@ -1116,7 +1111,6 @@ 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 +1133,12 @@ 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 +1268,8 @@ 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); }
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> --- v4: * used serdev_device_write_buf() instead of serdev_device_write() v3: * no change. v2: * Updated function qca_send_power_pulse() * addressed reviewer comments. v1: * initial patch --- drivers/bluetooth/hci_qca.c | 37 +++++++++++++------------------------ 1 file changed, 13 insertions(+), 24 deletions(-)