From c3f8d09d8f073331e49970b3a986804658e24d1d Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 29 May 2024 18:47:17 +0200 Subject: [PATCH] ALSA: ump: Set default protocol when not given explicitly BugLink: https://bugs.launchpad.net/bugs/2077600 [ Upstream commit bc42ca002d5d211f9c57334b9b4c25ddb0b4ec35 ] When an inquiry of the current protocol via UMP Stream Configuration message fails by some reason, we may leave the current protocol undefined, which may lead to unexpected behavior. Better to assume a valid protocol found in the protocol capability bits instead. For a device that doesn't support the UMP v1.2 feature, it won't reach to this code path, and USB MIDI GTB descriptor would be used for determining the protocol, instead. Link: https://lore.kernel.org/r/20240529164723.18309-2-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- sound/core/ump.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/sound/core/ump.c b/sound/core/ump.c index 3cd07c103d9e..d68d3bda97e4 100644 --- a/sound/core/ump.c +++ b/sound/core/ump.c @@ -967,6 +967,14 @@ int snd_ump_parse_endpoint(struct snd_ump_endpoint *ump) if (err < 0) ump_dbg(ump, "Unable to get UMP EP stream config\n"); + /* If no protocol is set by some reason, assume the valid one */ + if (!(ump->info.protocol & SNDRV_UMP_EP_INFO_PROTO_MIDI_MASK)) { + if (ump->info.protocol_caps & SNDRV_UMP_EP_INFO_PROTO_MIDI2) + ump->info.protocol |= SNDRV_UMP_EP_INFO_PROTO_MIDI2; + else if (ump->info.protocol_caps & SNDRV_UMP_EP_INFO_PROTO_MIDI1) + ump->info.protocol |= SNDRV_UMP_EP_INFO_PROTO_MIDI1; + } + /* Query and create blocks from Function Blocks */ for (blk = 0; blk < ump->info.num_blocks; blk++) { err = create_block_from_fb_info(ump, blk);