[pulseaudio-discuss] Questions about device_start_waiting_for_profiles

[Tanu Kaskinen]

On Sun, 2020-09-13 at 17:28 +0800, Chengyi Zhao wrote:
> Hi guys,
> 
> I have a question for the code below, please give your opinion, thanks!
> 
> The function device_start_waiting_for_profiles is to wait for connecting 
> profiles,
> but only waited 3 seconds(WAIT_FOR_PROFILES_TIMEOUT_USEC), if Bluetooth 
> transport state
> will be changed after 3 seconds(WAIT_FOR_PROFILES_TIMEOUT_USEC),
> I think whether there are any issues with the code logic or not.
> 
> 
>      /* src/modules/bluetooth/bluez5-util.c */
> 
>      n_disconnected_profiles = 
> device_count_disconnected_profiles(t->device);
> 
>      new_device_appeared = !old_any_connected && 
> pa_bluetooth_device_any_transport_connected(t->device);
>      device_disconnected = old_any_connected && 
> !pa_bluetooth_device_any_transport_connected(t->device);
> 
>      if (new_device_appeared) {
>          if (n_disconnected_profiles > 0)
>              device_start_waiting_for_profiles(t->device); <---- here
>          else
> pa_hook_fire(&t->device->discovery->hooks[PA_BLUETOOTH_HOOK_DEVICE_CONNECTION_CHANGED], 
> t->device);
>          return;
>      }
> 
>      static void device_start_waiting_for_profiles(pa_bluetooth_device 
> *device) {
>          pa_assert(!device->wait_for_profiles_timer);
>          device->wait_for_profiles_timer = 
> pa_core_rttime_new(device->discovery->core,
> pa_rtclock_now() + WAIT_FOR_PROFILES_TIMEOUT_USEC,  <---- here
> wait_for_profiles_cb, device);
>      }
> 
>      static void wait_for_profiles_cb(pa_mainloop_api *api, 
> pa_time_event* event, const struct timeval *tv, void *userdata) {
>          pa_bluetooth_device *device = userdata;
>          pa_strbuf *buf;
>          pa_bluetooth_profile_t profile;
>          bool first = true;
>          char *profiles_str;
> 
>          device_stop_waiting_for_profiles(device);  <---- here
> 
>          /* ...... */
>      }
> 
> Best Regards,
> Chengyi

I don't know what issues you're worried about. I'm not aware of any
issues, to my knowledge the code does what it's designed to do: delay
card creation until all profiles have been connected, but if that takes
more than 3 seconds, then the card is created with some profiles
disabled. We don't want to wait forever if those profiles never
connect.

-- 
Tanu

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