[pulseaudio-discuss] [PATCHv2 59/60] bluetooth: Fail to load driver is discovery module is not loaded

[João Paulo Rechi Vita]

On Mon, Aug 19, 2013 at 6:33 AM, Tanu Kaskinen
<tanu.kaskinen at linux.intel.com> wrote:
> There's a typo in the subject line: the first "is" should be "if". I
> also think "device" would be better than "driver", but that's
> nitpicking...
>

I'm changing only the "is" for "if".

> On Tue, 2013-08-13 at 01:54 -0300, jprvita at gmail.com wrote:
>> From: João Paulo Rechi Vita <jprvita at openbossa.org>
>>
>> For quite some time now the device driver module doesn't work well
>> without the discovery module, so for the BlueZ 5 support we'll prevent
>> the device driver module to be loaded if the discovery module is not
>> loaded.
>> ---
>>  src/modules/bluetooth/bluez5-util.c            | 3 ---
>>  src/modules/bluetooth/module-bluez5-device.c   | 7 ++++++-
>>  src/modules/bluetooth/module-bluez5-discover.c | 5 ++++-
>>  3 files changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/src/modules/bluetooth/bluez5-util.c b/src/modules/bluetooth/bluez5-util.c
>> index 3aad10f..3563d57 100644
>> --- a/src/modules/bluetooth/bluez5-util.c
>> +++ b/src/modules/bluetooth/bluez5-util.c
>> @@ -1420,9 +1420,6 @@ pa_bluetooth_discovery* pa_bluetooth_discovery_get(pa_core *c) {
>>      DBusConnection *conn;
>>      unsigned i;
>>
>> -    if ((y = pa_shared_get(c, "bluetooth-discovery")))
>> -        return pa_bluetooth_discovery_ref(y);
>> -
>>      y = pa_xnew0(pa_bluetooth_discovery, 1);
>>      PA_REFCNT_INIT(y);
>>      y->core = c;
>> diff --git a/src/modules/bluetooth/module-bluez5-device.c b/src/modules/bluetooth/module-bluez5-device.c
>> index dd9f40f..3c66c17 100644
>> --- a/src/modules/bluetooth/module-bluez5-device.c
>> +++ b/src/modules/bluetooth/module-bluez5-device.c
>> @@ -39,6 +39,7 @@
>>  #include <pulsecore/modargs.h>
>>  #include <pulsecore/poll.h>
>>  #include <pulsecore/rtpoll.h>
>> +#include <pulsecore/shared.h>
>>  #include <pulsecore/socket-util.h>
>>  #include <pulsecore/thread.h>
>>  #include <pulsecore/thread-mq.h>
>> @@ -1796,8 +1797,12 @@ int pa__init(pa_module* m) {
>>      u->core = m->core;
>>      u->modargs = ma;
>>
>> -    if (!(u->discovery = pa_bluetooth_discovery_get(m->core)))
>> +    if ((u->discovery = pa_shared_get(u->core, "bluetooth-discovery")))
>> +        pa_bluetooth_discovery_ref(u->discovery);
>> +    else {
>> +        pa_log_error("module-bluez5-discover doesn't seem to be loaded, refusing to load module-bluez5-device");
>>          goto fail;
>> +    }
>>
>>      if (!(u->device = pa_bluetooth_discovery_get_device_by_path(u->discovery, path))) {
>>          pa_log_error("%s is unknown", path);
>> diff --git a/src/modules/bluetooth/module-bluez5-discover.c b/src/modules/bluetooth/module-bluez5-discover.c
>> index e782b2e..a50b9ef 100644
>> --- a/src/modules/bluetooth/module-bluez5-discover.c
>> +++ b/src/modules/bluetooth/module-bluez5-discover.c
>> @@ -27,6 +27,7 @@
>>  #include <pulsecore/core-util.h>
>>  #include <pulsecore/macro.h>
>>  #include <pulsecore/module.h>
>> +#include <pulsecore/shared.h>
>>
>>  #include "bluez5-util.h"
>>
>> @@ -90,7 +91,9 @@ int pa__init(pa_module* m) {
>>      u->core = m->core;
>>      u->device_modules = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
>>
>> -    if (!(u->discovery = pa_bluetooth_discovery_get(u->core)))
>> +    if ((u->discovery = pa_shared_get(u->core, "bluetooth-discovery")))
>> +        pa_bluetooth_discovery_ref(u->discovery);
>> +    else if (!(u->discovery = pa_bluetooth_discovery_get(u->core)))
>>          goto fail;
>>
>>      u->device_connection_changed_slot =
>
> module-bluez5-discover doesn't load devices that already are known to
> pa_bluetooth_discovery. Perhaps it should do that, but I think it would
> be simpler and yet good enough to just make module-bluez5-discover the
> sole owner of pa_bluetooth_discovery. That means removing refcounting
> from pa_bluetooth_discovery. module-bluez5-device will have to be
> notified before pa_bluetooth_discovery is freed, so there should be hook
> PA_BLUETOOTH_HOOK_DISCOVERY_UNLINK or something like that.
>

How would a device be already known to pa_bluetooth_discovery when
module-bluez5-discover is loaded, if it is created by
module-bluez5-discover. We should even remove the pa_shared_get() in
module-bluez5-discover since it will always return NULL.

The refcounting is usefull if we want to unload module-bluez5-discover
when a device is already loaded. In this case it can continue to be
used, just new devices will not be discovered.

-- 
João Paulo Rechi Vita
http://about.me/jprvita