Re: [PATCH] android/handsfree: Delay SCO connection after codec negotiation

[Szymon Janc <szymon.janc@tieto.com>]

On Tuesday 28 of October 2014 12:27:48 Szymon Janc wrote:
> If SCO connection is created in same interation as OK response to
> AT+BCC it may happen that SCO will connect before OK is send. Some
> headset units don't handle this and reject SCO connection.
> 
> To fix that we delay SCO connection into next mainloop iteration.
> 
> Issue found on UPF49.
> 
> > ACL Data RX: Handle 2 flags 0x02 dlen 15                   [hci0]
> > 2572.477715
>       Channel: 66 len 11 [PSM 23 mode 0] {chan 2}
>         19 ef 0f 41 54 2b 42 43 43 0d 55                 ...AT+BCC.U
> < HCI Command: Setup Synchronous Co.. (0x01|0x0028) plen 17  [hci0]
> 2572.482384 Handle: 2
>         Transmit bandwidth: 8000
>         Receive bandwidth: 8000
>         Max latency: 13
>         Setting: 0x0003
>           Input Coding: Linear
>           Input Data Format: 1's complement
>           Input Sample Size: 8-bit
>           # of bits padding at MSB: 0
>           Air Coding Format: Transparent Data
>         Retransmission effort: Optimize for link quality (0x02)
>         Packet type: 0x0380
>           3-EV3 may not be used
>           2-EV5 may not be used
>           3-EV5 may not be used
> 
> > HCI Event: Command Status (0x0f) plen 4                    [hci0]
> > 2572.482903
>       Setup Synchronous Connection (0x01|0x0028) ncmd 1
>         Status: Success (0x00)
> < ACL Data TX: Handle 2 flags 0x00 dlen 14                   [hci0]
> 2572.490198 Channel: 6978 len 10 [PSM 3 mode 0] {chan 9}
>         1b ef 0d 0d 0a 4f 4b 0d 0a 8f                    .....OK...
> 
> > HCI Event: Number of Completed Packets (0x13) plen 5       [hci0]
> > 2572.493311
>         Num handles: 1
>         Handle: 2
>         Count: 1
> 
> > HCI Event: Synchronous Connect Complete (0x2c) plen 17     [hci0]
> > 2572.494013
>         Status: Connection Rejected due to Unacceptable BD_ADDR (0x0f)
>         Handle: 4
>         Address: 20:68:9D:30:7B:9F (Liteon Technology Corporation)
>         Link type: eSCO (0x02)
>         Transmission interval: 0x00
>         Retransmission window: 0x00
>         RX packet length: 0
>         TX packet length: 0
>         Air mode: CVSD (0x02)
> ---
>  android/handsfree.c | 50 +++++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 41 insertions(+), 9 deletions(-)
> 
> diff --git a/android/handsfree.c b/android/handsfree.c
> index 356dbe0..a42e0a0 100644
> --- a/android/handsfree.c
> +++ b/android/handsfree.c
> @@ -140,6 +140,7 @@ struct hf_device {
> 
>  	GIOChannel *sco;
>  	guint sco_watch;
> +	guint delay_sco;
>  };
> 
>  static const struct indicator inds_defaults[] = {
> @@ -254,6 +255,9 @@ static void device_destroy(struct hf_device *dev)
>  	if (dev->sco_watch)
>  		g_source_remove(dev->sco_watch);
> 
> +	if (dev->delay_sco)
> +		g_source_remove(dev->delay_sco);
> +
>  	if (dev->sco) {
>  		g_io_channel_shutdown(dev->sco, TRUE, NULL);
>  		g_io_channel_unref(dev->sco);
> @@ -1003,6 +1007,27 @@ static bool connect_sco(struct hf_device *dev)
>  	return true;
>  }
> 
> +static gboolean connect_sco_delayed(void *data)
> +{
> +	struct hf_device *dev = data;
> +
> +	DBG("");
> +
> +	dev->delay_sco = 0;
> +
> +	if (connect_sco(dev))
> +		return FALSE;
> +
> +	/*
> +	 * we try connect to negotiated codec. If it fails, and it isn't
> +	 * CVSD codec, try connect CVSD
> +	 */
> +	if (dev->negotiated_codec != CODEC_ID_CVSD)
> +		select_codec(dev, CODEC_ID_CVSD);
> +
> +	return FALSE;
> +}
> +
>  static void at_cmd_bcc(struct hfp_gw_result *result, enum hfp_gw_cmd_type
> type, void *user_data)
>  {
> @@ -1025,13 +1050,10 @@ static void at_cmd_bcc(struct hfp_gw_result *result,
> enum hfp_gw_cmd_type type, select_codec(dev, 0);
>  			return;
>  		}
> -		/*
> -		 * we try connect to negotiated codec. If it fails, and it isn't
> -		 * CVSD codec, try connect CVSD
> -		 */
> -		if (!connect_sco(dev) && dev->negotiated_codec != CODEC_ID_CVSD)
> -			select_codec(dev, CODEC_ID_CVSD);
> 
> +		/* Delay SCO connection so that OK response is send first */
> +		if (dev->delay_sco == 0)
> +			dev->delay_sco = g_idle_add(connect_sco_delayed, dev);
>  		return;
>  	case HFP_GW_CMD_TYPE_READ:
>  	case HFP_GW_CMD_TYPE_TEST:
> @@ -1069,8 +1091,12 @@ static void at_cmd_bcs(struct hfp_gw_result *result,
> enum hfp_gw_cmd_type type,
> 
>  		hfp_gw_send_result(dev->gw, HFP_RESULT_OK);
> 
> -		/* Connect sco with negotiated parameters */
> -		connect_sco(dev);
> +		/*
> +		 * Delay SCO connection so that OK response is send first,
> +		 * then connect with negotiated parameters.
> +		 */
> +		if (dev->delay_sco == 0)
> +			dev->delay_sco = g_idle_add(connect_sco_delayed, dev);
>  		return;
>  	case HFP_GW_CMD_TYPE_READ:
>  	case HFP_GW_CMD_TYPE_TEST:
> @@ -1741,8 +1767,14 @@ failed:
> 
>  static bool disconnect_sco(struct hf_device *dev)
>  {
> -	if (!dev->sco)
> +	if (!dev->sco) {
> +		if (dev->delay_sco) {
> +			g_source_remove(dev->delay_sco);
> +			dev->delay_sco = 0;
> +		}
> +
>  		return false;
> +	}
> 
>  	set_audio_state(dev, HAL_EV_HANDSFREE_AUDIO_STATE_DISCONNECTING);

Pushed.

-- 
BR
Szymon Janc