From: Takashi Iwai <tiwai@suse.de>
To: happy.debugging@gmail.com
Cc: alsa-devel@alsa-project.org
Subject: Re: [PATCH v2 00/37] ALSA: Add MIDI 2.0 support
Date: Tue, 13 Jun 2023 14:53:17 +0200 [thread overview]
Message-ID: <87o7ljplqa.wl-tiwai@suse.de> (raw)
In-Reply-To: <168666006765.22.17667904471972537472@mailman-web.alsa-project.org>
On Tue, 13 Jun 2023 14:41:07 +0200,
happy.debugging@gmail.com wrote:
>
> Hello I have a few questions:
>
> 1. As default, USB-audio driver will take the alternate setting for MIDI 2.0 interface: Does this mean that the ALSA driver will default to Alt Function 1 if it exists ?
Yes.
> 2. What happens when using a kernel that does not support Alt Function 1 (MIDI 2.0) and device with a (much longer) MIDI 2.0 descriptor is attached ?
It falls back to MIDI 1.0 interface.
> 3. " However, user may let the driver falling back to the old MIDI 1.0 interface by a module option, too."
> Can or how it this done via the ALSA API ?
You can't. Only via a module option or kconfig.
> If the switch is made, does an ALSA client require to re-enumerate all the ports ?
> 4. Is there a way to force a specific device (port) to Legacy MIDI 1.0 ?
If demanded, we can implement a device-specific quirk for that.
> 5. Is there a way , via ALSA, to select UMP MIDI 1.0 protocol instead of MIDI 2.0 UMP protocol.
Use the UMP 1.1 Streaming command to switch the protocol.
> 6. To which protocol does the driver default ? UMP MIDI 1.0 or UMP MIDI 2.0 ?
Whatever the device sets as default.
> 7. Does the driver do anything related to Jitter Reduction ? How/is this supported via the ALSA API ?a
JRTS is sent as normal UMP packet (also as sequencer events).
No particular API is provided for JRTS, so far.
> 8. Does the driver do anything related to Bandwidth restriction ? How/is this supported via the ALSA API ?
Currently no restriction is.
The bandwidth is provided via the API, but it's only for information.
> 9. Are/will UMP streaming messages be supported ? (new feature in MIDI 2.0 specification), if yes, how ?
It was already implemented in kernel UMP core. See the recent posts.
> 10. Is function block information supported via ALSA, i.e added in the ALSA Port information ?
Ditto.
Takashi
next prev parent reply other threads:[~2023-06-13 12:54 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-23 7:53 [PATCH v2 00/37] ALSA: Add MIDI 2.0 support Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 01/37] ALSA: rawmidi: Pass rawmidi directly to snd_rawmidi_kernel_open() Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 02/37] ALSA: rawmidi: Add ioctl callback to snd_rawmidi_global_ops Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 03/37] ALSA: rawmidi: UMP support Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 04/37] ALSA: rawmidi: Skip UMP devices at SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 05/37] ALSA: ump: Add ioctls to inquiry UMP EP and Block info via control API Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 06/37] ALSA: ump: Additional proc output Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 07/37] ALSA: usb-audio: Manage number of rawmidis globally Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 08/37] ALSA: usb-audio: Define USB MIDI 2.0 specs Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 09/37] ALSA: usb-audio: USB MIDI 2.0 UMP support Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 10/37] ALSA: usb-audio: Get UMP EP name string from USB interface Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 11/37] ALSA: usb-audio: Trim superfluous "MIDI" suffix from UMP EP name Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 12/37] ALSA: usb-audio: Create UMP blocks from USB MIDI GTBs Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 13/37] ALSA: ump: Redirect rawmidi substream access via own helpers Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 14/37] ALSA: ump: Add legacy raw MIDI support Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 15/37] ALSA: usb-audio: Enable the " Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 16/37] ALSA: usb-audio: Inform inconsistent protocols in GTBs Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 17/37] ALSA: seq: Clear padded bytes at expanding events Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 18/37] ALSA: seq: Add snd_seq_expand_var_event_at() helper Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 19/37] ALSA: seq: Treat snd_seq_client object directly in client drivers Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 20/37] ALSA: seq: Drop dead code for the old broadcast support Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 21/37] ALSA: seq: Check the conflicting port at port creation Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 22/37] ALSA: seq: Check validity before creating a port object Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 23/37] ALSA: seq: Prohibit creating ports with special numbers Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 24/37] ALSA: seq: Introduce SNDRV_SEQ_IOCTL_USER_PVERSION ioctl Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 25/37] ALSA: seq: Add UMP support Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 26/37] ALSA: seq: Add port inactive flag Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 27/37] ALSA: seq: Support MIDI 2.0 UMP Endpoint port Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 28/37] ALSA: seq: Add port direction to snd_seq_port_info Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 29/37] ALSA: seq: Add UMP group number " Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 30/37] ALSA: seq: Automatic conversion of UMP events Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 31/37] ALSA: seq: Allow suppressing UMP conversions Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 32/37] ALSA: seq: Bind UMP device Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 33/37] ALSA: seq: ump: Create UMP Endpoint port for broadcast Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 34/37] ALSA: seq: Add ioctls for client UMP info query and setup Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 35/37] ALSA: seq: Print UMP Endpoint and Block information in proc outputs Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 36/37] ALSA: seq: Add UMP group filter Takashi Iwai
2023-05-23 7:53 ` [PATCH v2 37/37] ALSA: docs: Add MIDI 2.0 documentation Takashi Iwai
2023-06-13 12:41 ` [PATCH v2 00/37] ALSA: Add MIDI 2.0 support happy.debugging
2023-06-13 12:53 ` Takashi Iwai [this message]
2023-06-13 13:24 ` Happy Debugging
2023-06-13 13:31 ` Takashi Iwai
2023-06-13 15:23 ` Symbolic Debugger
2023-06-14 6:01 ` Symbolic Debugger
2023-06-14 6:09 ` Takashi Iwai
2023-06-14 6:53 ` Takashi Iwai
2023-06-15 11:39 ` Symbolic Debugger
2023-06-16 12:23 ` Symbolic Debugger
2023-06-16 12:27 ` Takashi Iwai
2023-06-16 14:17 ` Symbolic Debugger
2023-06-17 15:07 ` Symbolic Debugger
2023-06-18 8:54 ` Takashi Iwai
2023-06-20 13:29 ` Symbolic Debugger
2023-06-28 6:52 ` Symbolic Debugger
2023-06-28 11:12 ` Takashi Iwai
2023-06-28 11:32 ` Symbolic Debugger
2023-06-28 14:20 ` Takashi Iwai
2023-06-29 2:03 ` Symbolic Debugger
2023-06-29 6:40 ` Takashi Iwai
2023-06-29 8:38 ` Symbolic Debugger
2023-07-03 10:15 ` Symbolic Debugger
2023-07-03 10:19 ` Takashi Iwai
2023-07-03 11:25 ` Symbolic Debugger
2023-07-03 12:09 ` Takashi Iwai
2023-07-03 12:54 ` Symbolic Debugger
2023-07-03 13:01 ` Takashi Iwai
2023-07-03 13:53 ` Symbolic Debugger
2023-07-12 13:26 ` Symbolic Debugger
2023-07-12 13:58 ` Takashi Iwai
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