Hi, It seems that if media application is registered to multiple BT adapters, BlueZ can easily run out of free AVDTP SEIDs. This occurs in practice when running Pipewire (or Pulseaudio) and plugging in 3+ adapters: their media application has 10+ SEPs for various vendor A2DP codecs, registered for each adapter. After having registered 32 SEPs across all adapters, Media1.RegisterApplication starts failing, due to SEP registration not finding free SEIDs. However, if I understand the AVDTP spec and BlueZ implementation correctly, this behavior is not quite correct: (i) the SEID pool in BlueZ is limited to 8*sizeof(int) == 32 entries, which is smaller than the 0x3E = 62 entries (AVDTP1.3, 8.20.1). Also, (ii) BlueZ allocates SEIDs from a pool shared by all adapters, whereas it seems they should be device & connection local (AVDTP1.3, 4.10). Since adapters are separate devices in this context, this then appears to imply that each should have separate SEID pool. If this interpretation is right (I don't know the AVDTP spec very well, so...), here are two patches that address this. In (limited) tests this seemed to work. Pauli Virtanen (2): shared/util: use 64-bit bitmap in util_get/clear_uid avdtp: use separate local SEID pool for each adapter android/avdtp.c | 2 +- profiles/audio/a2dp.c | 2 +- profiles/audio/avdtp.c | 55 ++++++++++++++++++++++++++++++++++++------ profiles/audio/avdtp.h | 4 ++- src/advertising.c | 2 +- src/shared/util.c | 27 ++++++++++++--------- src/shared/util.h | 4 +-- unit/test-avdtp.c | 2 +- 8 files changed, 71 insertions(+), 27 deletions(-) -- 2.31.1
