Re: [PATCH v6 3/6] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

2018-12-27 Thread Balakrishna Godavarthi 

Hi Matthias,

On 2018-12-28 01:55, Matthias Kaehlcke wrote:

On Thu, Dec 27, 2018 at 01:01:33PM +0530, Balakrishna Godavarthi wrote:

During initalization of wcn3990, we observed UART is reading some
stray bytes on the Rx line. This is logging Frame reassembly errors
on the serial console. This could be because of tristate of Tx line
of wcn3990 during boot up.


My testing suggests that this change is not needed if the Rx line of
the SoC/AP is configured with a pull-up. We'd probably all prefer not
to have this change if there's a neater way to address the garbage
data. Could you test with adding the pull-up and dropping this patch
on your side?

Thanks

Matthias


Thanks a lot it worked to me. will drop this patch.

--
Regards
Balakrishna.

Re: [PATCH v6 3/6] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

2018-12-27 Thread Matthias Kaehlcke 
On Thu, Dec 27, 2018 at 01:01:33PM +0530, Balakrishna Godavarthi wrote:
> During initalization of wcn3990, we observed UART is reading some
> stray bytes on the Rx line. This is logging Frame reassembly errors
> on the serial console. This could be because of tristate of Tx line
> of wcn3990 during boot up.

My testing suggests that this change is not needed if the Rx line of
the SoC/AP is configured with a pull-up. We'd probably all prefer not
to have this change if there's a neater way to address the garbage
data. Could you test with adding the pull-up and dropping this patch
on your side?

Thanks

Matthias

[PATCH v6 3/6] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

2018-12-26 Thread Balakrishna Godavarthi 
During initalization of wcn3990, we observed UART is reading some
stray bytes on the Rx line. This is logging Frame reassembly errors
on the serial console. This could be because of tristate of Tx line
of wcn3990 during boot up.

[  176.929612] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed 
(-84)
[  176.945734] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed 
(-84)
[  176.953298] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed 
(-84)
[  177.010660] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed 
(-84)
[  177.067633] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed 
(-84)

Now we enable a flag during bootup to stop executing proto receive
function and clear it back once the initialization is done.

Signed-off-by: Balakrishna Godavarthi 
Tested-by: Matthias Kaehlcke 
---
 drivers/bluetooth/hci_qca.c | 16 
 1 file changed, 16 insertions(+)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 63436023632d..0751b2359f6f 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -56,6 +56,7 @@
 
 /* Controller states */
 #define STATE_IN_BAND_SLEEP_ENABLED1
+#define STATE_DISCARD_RX   2
 
 #define IBS_WAKE_RETRANS_TIMEOUT_MS100
 #define IBS_TX_IDLE_TIMEOUT_MS 2000
@@ -511,6 +512,7 @@ static int qca_open(struct hci_uart *hu)
} else {
hu->init_speed = qcadev->init_speed;
hu->oper_speed = qcadev->oper_speed;
+   set_bit(STATE_DISCARD_RX, >flags);
ret = qca_power_setup(hu, true);
if (ret) {
destroy_workqueue(qca->workqueue);
@@ -903,6 +905,13 @@ static int qca_recv(struct hci_uart *hu, const void *data, 
int count)
if (!test_bit(HCI_UART_REGISTERED, >flags))
return -EUNATCH;
 
+   /* We discard Rx data received while device is in booting
+* stage, This is because of BT chip Tx line is in tristate.
+* Due to this we read some garbage data on UART Rx.
+*/
+   if (test_bit(STATE_DISCARD_RX, >flags))
+   return 0;
+
qca->rx_skb = h4_recv_buf(hu->hdev, qca->rx_skb, data, count,
  qca_recv_pkts, ARRAY_SIZE(qca_recv_pkts));
if (IS_ERR(qca->rx_skb)) {
@@ -1195,6 +1204,7 @@ static int qca_setup(struct hci_uart *hu)
if (ret)
return ret;
 
+   clear_bit(STATE_DISCARD_RX, >flags);
ret = qca_read_soc_version(hdev, _ver);
if (ret)
return ret;
@@ -1271,6 +1281,12 @@ static const struct qca_vreg_data qca_soc_data = {
 
 static void qca_power_shutdown(struct hci_uart *hu)
 {
+   struct qca_data *qca = hu->priv;
+
+   /* From this point we go into power off state. But serial port is
+* still open, discard all the garbage data received on the Rx line.
+*/
+   set_bit(STATE_DISCARD_RX, >flags);
host_set_baudrate(hu, 2400);
qca_send_power_pulse(hu, QCA_WCN3990_POWEROFF_PULSE);
qca_power_setup(hu, false);
-- 
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