[PATCH v2] shared/asha: prime volume before starting audio

[Kyle Pepper <cochcoder@proton.me>]

Prime the Volume characteristic with the cached volume before START so
both volume inputs are initialized when audio starts. Keep the write
best effort so a rejected volume write does not prevent START.

Assisted-by: OpenCode:gpt-6.1-sol
Assisted-by: Codex:gpt-6
---
v2: Drop the standalone mock test and redundant failure log.

Previous version:
https://lore.kernel.org/linux-bluetooth/20261028133131.262033-1-cochcoder@proton.me/

The unchanged local harness rejects baseline and passes this version,
including ASan/UBSan and LTO checks. Full make check is blocked by an SDP
debug-symbol linker failure also reproduced on unchanged upstream.
No volume-only hardware ablation or new remote CI result is claimed.

 src/shared/asha.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/shared/asha.c b/src/shared/asha.c
index 79bb29bf9a..6310a8357d 100644
--- a/src/shared/asha.c
+++ b/src/shared/asha.c
@@ -262,6 +262,9 @@ unsigned int bt_asha_start(struct bt_asha *asha, bt_asha_cb_t cb,
 		return 0;
 	}
 
+	/* Some renderers require a Volume write before START. */
+	bt_asha_set_volume(asha, asha->volume);
+
 	ret = asha_send_acp(asha, acp_start_cmd, sizeof(acp_start_cmd), cb,
 			user_data);
 	if (ret < 0)

base-commit: a8067198717b38391ca183ed7f41a69ec4b81b6e
-- 
2.56.0