[PATCH BlueZ] audio/avrcp: fix EVENT_VOLUME_CHANGED not supported

[PATCH BlueZ] audio/avrcp: fix EVENT_VOLUME_CHANGED not supported

[Pavel Bozhko]

Some devices with AVRCP 1.3 may support remote volume
control—for example, certain TV models such as:
- LG webOS TV UM7450PLA
- Xiaomi Mi TV 4A 43
when they act as the audio source, provided that
Category 2 (Monitor/Amplifier) functionality is supported.
---
 profiles/audio/avrcp.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/profiles/audio/avrcp.c b/profiles/audio/avrcp.c
index 724b46c59..d501315b6 100644
--- a/profiles/audio/avrcp.c
+++ b/profiles/audio/avrcp.c
@@ -1765,10 +1765,11 @@ err:
 	return AVC_CTYPE_REJECTED;
 }
 
-/* SetAbsoluteVolume requires at least version 1.4 and a category-2 */
+/* SetAbsoluteVolume requires at least version 1.4 and or category-2 */
 static bool avrcp_volume_supported(struct avrcp_data *data)
 {
-	if (!data || data->version < 0x0104)
+	if (!data || (data->version < 0x0104 &&
+		!(data->features & AVRCP_FEATURE_CATEGORY_2)))
 		return false;
 
 	if (btd_opts.avrcp.volume_category &&
@@ -4293,13 +4294,13 @@ static void target_init(struct avrcp *session)
 				(1 << AVRCP_EVENT_TRACK_REACHED_END) |
 				(1 << AVRCP_EVENT_SETTINGS_CHANGED);
 
-	if (target->version < 0x0104)
-		return;
-
 	if (avrcp_volume_supported(target))
 		session->supported_events |=
 				(1 << AVRCP_EVENT_VOLUME_CHANGED);
 
+	if (target->version < 0x0104)
+		return;
+
 	session->supported_events |=
 				(1 << AVRCP_EVENT_ADDRESSED_PLAYER_CHANGED) |
 				(1 << AVRCP_EVENT_AVAILABLE_PLAYERS_CHANGED);
-- 
2.50.1 (Apple Git-155)

RE: [BlueZ] audio/avrcp: fix EVENT_VOLUME_CHANGED not supported

[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=1059867

---Test result---

Test Summary:
CheckPatch                    PENDING   0.35 seconds
GitLint                       PENDING   0.53 seconds
BuildEll                      PASS      20.71 seconds
BluezMake                     PASS      634.60 seconds
MakeCheck                     PASS      18.88 seconds
MakeDistcheck                 PASS      245.24 seconds
CheckValgrind                 PASS      295.57 seconds
CheckSmatch                   PASS      360.31 seconds
bluezmakeextell               PASS      181.51 seconds
IncrementalBuild              PENDING   0.44 seconds
ScanBuild                     PASS      1031.10 seconds

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

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

##############################
Test: IncrementalBuild - PENDING
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Output:



---
Regards,
Linux Bluetooth

Re: [PATCH BlueZ] audio/avrcp: fix EVENT_VOLUME_CHANGED not supported

[Luiz Augusto von Dentz]

Hi Pavel,

On Mon, Mar 2, 2026 at 4:23 AM Pavel Bozhko <pvbozhko@salutedevices.com> wrote:
>
> Some devices with AVRCP 1.3 may support remote volume
> control—for example, certain TV models such as:
> - LG webOS TV UM7450PLA
> - Xiaomi Mi TV 4A 43
> when they act as the audio source, provided that
> Category 2 (Monitor/Amplifier) functionality is supported.

Just because these device do this way doesn't mean they are compliant,
afaik SetAbsoluteVolume and  EVENT_VOLUME_CHANGED were introduced in
1.4 so there is no way for 1.3 to support them.

> ---
>  profiles/audio/avrcp.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/profiles/audio/avrcp.c b/profiles/audio/avrcp.c
> index 724b46c59..d501315b6 100644
> --- a/profiles/audio/avrcp.c
> +++ b/profiles/audio/avrcp.c
> @@ -1765,10 +1765,11 @@ err:
>         return AVC_CTYPE_REJECTED;
>  }
>
> -/* SetAbsoluteVolume requires at least version 1.4 and a category-2 */
> +/* SetAbsoluteVolume requires at least version 1.4 and or category-2 */
>  static bool avrcp_volume_supported(struct avrcp_data *data)
>  {
> -       if (!data || data->version < 0x0104)
> +       if (!data || (data->version < 0x0104 &&
> +               !(data->features & AVRCP_FEATURE_CATEGORY_2)))
>                 return false;
>
>         if (btd_opts.avrcp.volume_category &&
> @@ -4293,13 +4294,13 @@ static void target_init(struct avrcp *session)
>                                 (1 << AVRCP_EVENT_TRACK_REACHED_END) |
>                                 (1 << AVRCP_EVENT_SETTINGS_CHANGED);
>
> -       if (target->version < 0x0104)
> -               return;
> -
>         if (avrcp_volume_supported(target))
>                 session->supported_events |=
>                                 (1 << AVRCP_EVENT_VOLUME_CHANGED);
>
> +       if (target->version < 0x0104)
> +               return;
> +
>         session->supported_events |=
>                                 (1 << AVRCP_EVENT_ADDRESSED_PLAYER_CHANGED) |
>                                 (1 << AVRCP_EVENT_AVAILABLE_PLAYERS_CHANGED);
> --
> 2.50.1 (Apple Git-155)
>
>


-- 
Luiz Augusto von Dentz

Re: [PATCH BlueZ] audio/avrcp: fix EVENT_VOLUME_CHANGED not supported

[Luiz Augusto von Dentz]

Hi Pavel,

On Tue, Mar 3, 2026 at 1:57 PM Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
>
> Hi Pavel,
>
> On Mon, Mar 2, 2026 at 4:23 AM Pavel Bozhko <pvbozhko@salutedevices.com> wrote:
> >
> > Some devices with AVRCP 1.3 may support remote volume
> > control—for example, certain TV models such as:
> > - LG webOS TV UM7450PLA
> > - Xiaomi Mi TV 4A 43
> > when they act as the audio source, provided that
> > Category 2 (Monitor/Amplifier) functionality is supported.
>
> Just because these device do this way doesn't mean they are compliant,
> afaik SetAbsoluteVolume and  EVENT_VOLUME_CHANGED were introduced in
> 1.4 so there is no way for 1.3 to support them.

Just confirmed, they don't appear in 1.3:

https://www.bluetooth.com/specifications/specs/a-v-remote-control-profile-1-3/

Maybe you are suggesting that we automatically bump their version if
we see such usage, while this could work there is also the possibility
of qualification tests to start to cover such behavior and require
failing, so we might need some setting if want to allow version
upgrade like this.

> > ---
> >  profiles/audio/avrcp.c | 11 ++++++-----
> >  1 file changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/profiles/audio/avrcp.c b/profiles/audio/avrcp.c
> > index 724b46c59..d501315b6 100644
> > --- a/profiles/audio/avrcp.c
> > +++ b/profiles/audio/avrcp.c
> > @@ -1765,10 +1765,11 @@ err:
> >         return AVC_CTYPE_REJECTED;
> >  }
> >
> > -/* SetAbsoluteVolume requires at least version 1.4 and a category-2 */
> > +/* SetAbsoluteVolume requires at least version 1.4 and or category-2 */
> >  static bool avrcp_volume_supported(struct avrcp_data *data)
> >  {
> > -       if (!data || data->version < 0x0104)
> > +       if (!data || (data->version < 0x0104 &&
> > +               !(data->features & AVRCP_FEATURE_CATEGORY_2)))
> >                 return false;
> >
> >         if (btd_opts.avrcp.volume_category &&
> > @@ -4293,13 +4294,13 @@ static void target_init(struct avrcp *session)
> >                                 (1 << AVRCP_EVENT_TRACK_REACHED_END) |
> >                                 (1 << AVRCP_EVENT_SETTINGS_CHANGED);
> >
> > -       if (target->version < 0x0104)
> > -               return;
> > -
> >         if (avrcp_volume_supported(target))
> >                 session->supported_events |=
> >                                 (1 << AVRCP_EVENT_VOLUME_CHANGED);
> >
> > +       if (target->version < 0x0104)
> > +               return;
> > +
> >         session->supported_events |=
> >                                 (1 << AVRCP_EVENT_ADDRESSED_PLAYER_CHANGED) |
> >                                 (1 << AVRCP_EVENT_AVAILABLE_PLAYERS_CHANGED);
> > --
> > 2.50.1 (Apple Git-155)
> >
> >
>
>
> --
> Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz