[PATCH v1] device: Initialize device volume with a valid value

[PATCH v1] device: Initialize device volume with a valid value

[Jinwang Li]

When AVRCP is connected earlier than AVDTP, this invalid device volume
causes the A2DP sink to reject the peer's registration for the
EVENT_VOLUME_CHANGED notification. As a result, subsequent attempts to
set the volume fail.

Fixes: fa7828bddd21 ("transport: Fix not being able to initialize volume properly")
Signed-off-by: Jinwang Li <jinwang.li@oss.qualcomm.com>
---
 src/device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/device.c b/src/device.c
index af8df5f29..cd0b8802e 100644
--- a/src/device.c
+++ b/src/device.c
@@ -4948,7 +4948,7 @@ static struct btd_device *device_new(struct btd_adapter *adapter,
 		return NULL;
 
 	device->tx_power = 127;
-	device->volume = -1;
+	device->volume = 127;
 	device->wake_id = -1U;
 
 	device->db = gatt_db_new();
-- 
2.34.1

RE: [v1] device: Initialize device volume with a valid value

[bluez.test.bot]

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Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1045489

---Test result---

Test Summary:
CheckPatch                    PENDING   0.37 seconds
GitLint                       PENDING   0.38 seconds
BuildEll                      PASS      20.13 seconds
BluezMake                     PASS      650.70 seconds
MakeCheck                     PASS      18.79 seconds
MakeDistcheck                 PASS      244.71 seconds
CheckValgrind                 PASS      296.47 seconds
CheckSmatch                   PASS      355.04 seconds
bluezmakeextell               PASS      184.47 seconds
IncrementalBuild              PENDING   0.33 seconds
ScanBuild                     PASS      1040.61 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
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Desc: Run gitlint
Output:

##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH v1] device: Initialize device volume with a valid value

[Jinwang Li]

On 1/22/2026 2:36 PM, Jinwang Li wrote:
> When AVRCP is connected earlier than AVDTP, this invalid device volume
> causes the A2DP sink to reject the peer's registration for the
> EVENT_VOLUME_CHANGED notification. As a result, subsequent attempts to
> set the volume fail.
> 
> Fixes: fa7828bddd21 ("transport: Fix not being able to initialize volume properly")
> Signed-off-by: Jinwang Li <jinwang.li@oss.qualcomm.com>
> ---
>   src/device.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/device.c b/src/device.c
> index af8df5f29..cd0b8802e 100644
> --- a/src/device.c
> +++ b/src/device.c
> @@ -4948,7 +4948,7 @@ static struct btd_device *device_new(struct btd_adapter *adapter,
>   		return NULL;
>   
>   	device->tx_power = 127;
> -	device->volume = -1;
> +	device->volume = 127;
>   	device->wake_id = -1U;
>   
>   	device->db = gatt_db_new();

Hi maintainers,

Do you have any comments on this change?

--
with best wishes
Jinwang

Re: [PATCH v1] device: Initialize device volume with a valid value

[Luiz Augusto von Dentz]

Hi Jinwang,

On Thu, Jan 22, 2026 at 1:44 AM Jinwang Li <jinwang.li@oss.qualcomm.com> wrote:
>
> When AVRCP is connected earlier than AVDTP, this invalid device volume
> causes the A2DP sink to reject the peer's registration for the
> EVENT_VOLUME_CHANGED notification. As a result, subsequent attempts to
> set the volume fail.
>
> Fixes: fa7828bddd21 ("transport: Fix not being able to initialize volume properly")
> Signed-off-by: Jinwang Li <jinwang.li@oss.qualcomm.com>
> ---
>  src/device.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/device.c b/src/device.c
> index af8df5f29..cd0b8802e 100644
> --- a/src/device.c
> +++ b/src/device.c
> @@ -4948,7 +4948,7 @@ static struct btd_device *device_new(struct btd_adapter *adapter,
>                 return NULL;
>
>         device->tx_power = 127;
> -       device->volume = -1;
> +       device->volume = 127;

This represents the volume of the remote end. Why would we initialize
with max volume if we don't know its volume? I guess this depends on
the role though since transport_a2dp_src_init and
transport_a2dp_snk_init do initialize the volume with -1 and 127
respectively, so as a sink perhaps it would be correct to initialize
with max volume so we may need to replicate the same behavior.

>         device->wake_id = -1U;
>
>         device->db = gatt_db_new();
> --
> 2.34.1
>
>


-- 
Luiz Augusto von Dentz

Re: [PATCH v1] device: Initialize device volume with a valid value

[Jinwang Li]

Hi Luiz,

On 2/25/2026 10:52 PM, Luiz Augusto von Dentz wrote:
> Hi Jinwang,
> 
> On Thu, Jan 22, 2026 at 1:44 AM Jinwang Li <jinwang.li@oss.qualcomm.com> wrote:
>>
>> When AVRCP is connected earlier than AVDTP, this invalid device volume
>> causes the A2DP sink to reject the peer's registration for the
>> EVENT_VOLUME_CHANGED notification. As a result, subsequent attempts to
>> set the volume fail.
>>
>> Fixes: fa7828bddd21 ("transport: Fix not being able to initialize volume properly")
>> Signed-off-by: Jinwang Li <jinwang.li@oss.qualcomm.com>
>> ---
>>   src/device.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/src/device.c b/src/device.c
>> index af8df5f29..cd0b8802e 100644
>> --- a/src/device.c
>> +++ b/src/device.c
>> @@ -4948,7 +4948,7 @@ static struct btd_device *device_new(struct btd_adapter *adapter,
>>                  return NULL;
>>
>>          device->tx_power = 127;
>> -       device->volume = -1;
>> +       device->volume = 127;
> 
> This represents the volume of the remote end. Why would we initialize
> with max volume if we don't know its volume? I guess this depends on
> the role though since transport_a2dp_src_init and
> transport_a2dp_snk_init do initialize the volume with -1 and 127
> respectively, so as a sink perhaps it would be correct to initialize
> with max volume so we may need to replicate the same behavior.
> 
>>          device->wake_id = -1U;
>>
>>          device->db = gatt_db_new();
>> --
>> 2.34.1
>>
>>
> 
> 
When AVRCP is established before A2DP, the role is not yet known, so it 
is unclear which volume should be used. However, rejecting the Volume 
Changed RegisterNotification prevents any later volume synchronization.

Returning a valid volume from media_transport_get_a2dp_volume() when
there is no A2DP transport and the device volume is -1 seems reasonable.
Would using the maximum volume make sense?

I have updated the change to
"[PATCH v2] transport: Fix set volume failure with invalid device volume".


Thanks,
Jinwang