From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F1A9328619 for ; Thu, 16 Oct 2025 10:53:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760611993; cv=none; b=E1WD56wW6gMnP0HcZvO5p4jpf7JUaYVMdUxfyUb6Oc/YR4FTQab3L7G6xmUf4/fieBQX2TWrCPSd18oVGBEz8I7OYlzcjJ4TJF/yPmEnQ+IiNZvipNHxRrzhA5f/VmgNnch+ChL/jKS0MfugTDHk6d8VZ/URS8P9fryzR3aQHNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760611993; c=relaxed/simple; bh=L4IUjh7qvoEdFkzHuAvVgeqtOfEamA6IIYKcdRm7gAw=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=FicxlqaHrrYrL3KRmazMLAs5i3CNXvl4gD4ZgYXaAsyRL7N+TwTuV/aXq49rq5ZRWW62iv6bAKAmjdLd2BGhiHJLYiuX7F368P3+BZYxEkxna6wXoCEuCcNjeLRC3M/oZVvBEZBFyQLHYcbNSVp6bNkgVtrPBNp3WrjklRo5/Fk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=tSX7wToO; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=y9EHFkVQ; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=tSX7wToO; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=y9EHFkVQ; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="tSX7wToO"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="y9EHFkVQ"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="tSX7wToO"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="y9EHFkVQ" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 44EBB21DB7; Thu, 16 Oct 2025 10:53:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1760611985; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4ccNdWmfmDRImTgiOmSYnLQj4cEM0AwtCLQkoK0yeeo=; b=tSX7wToORyIiUAqFEmPaG5D8JDMkJS+WuiJH0gnydD8ppOW5V8s0forAr3K4hTXBmDbLu1 1c3QRt+xvCIeuDIIcwiLYZPMMg7qR5uB6G17rM7cNwPwm8B5lguwbwuLjOjrJw2nJff2aJ cdepMsTPz7h9E4aTV8agLWJGIrOwiWs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1760611985; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4ccNdWmfmDRImTgiOmSYnLQj4cEM0AwtCLQkoK0yeeo=; b=y9EHFkVQXXZXTvPB9RRXnMi+YPbXX+KBmaQG16L1dOiY/c+5uBqAxevi79td5RZgKl3/Ho u7vkbjDGwng+VVCQ== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1760611985; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4ccNdWmfmDRImTgiOmSYnLQj4cEM0AwtCLQkoK0yeeo=; b=tSX7wToORyIiUAqFEmPaG5D8JDMkJS+WuiJH0gnydD8ppOW5V8s0forAr3K4hTXBmDbLu1 1c3QRt+xvCIeuDIIcwiLYZPMMg7qR5uB6G17rM7cNwPwm8B5lguwbwuLjOjrJw2nJff2aJ cdepMsTPz7h9E4aTV8agLWJGIrOwiWs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1760611985; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4ccNdWmfmDRImTgiOmSYnLQj4cEM0AwtCLQkoK0yeeo=; b=y9EHFkVQXXZXTvPB9RRXnMi+YPbXX+KBmaQG16L1dOiY/c+5uBqAxevi79td5RZgKl3/Ho u7vkbjDGwng+VVCQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 23A091376E; Thu, 16 Oct 2025 10:53:05 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id jjBpB5HO8GjJKAAAD6G6ig (envelope-from ); Thu, 16 Oct 2025 10:53:05 +0000 Date: Thu, 16 Oct 2025 12:53:04 +0200 Message-ID: <874irz86en.wl-tiwai@suse.de> From: Takashi Iwai To: Pawel / Xj Cc: linux-sound Subject: Re: [BUG] Presonus Studio 1824c firmware 3.11 no longer exposes mixer interface ("Quirk or no altset; falling back to MIDI 1.0") In-Reply-To: <515e134e2b0a4364b6d595c77ef84216@grupawp.pl> References: <515e134e2b0a4364b6d595c77ef84216@grupawp.pl> User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.2 Mule/6.0 Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=ISO-2022-JP X-Spam-Level: X-Spamd-Result: default: False [-3.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; FUZZY_RATELIMITED(0.00)[rspamd.com]; TO_DN_ALL(0.00)[]; FREEMAIL_TO(0.00)[wp.pl]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RCPT_COUNT_TWO(0.00)[2]; ARC_NA(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FREEMAIL_ENVRCPT(0.00)[wp.pl]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:mid,imap1.dmz-prg2.suse.org:helo] X-Spam-Flag: NO X-Spam-Score: -3.30 On Thu, 16 Oct 2025 01:18:55 +0200, Pawel / Xj wrote: > > > Hi ALSA developers, > > after upgrading the firmware on my PreSonus Studio 1824c audio interface to > version 3.11, > the Linux USB-audio driver no longer attaches the mixer/routing interface. > > On kernels 6.17.0 and 6.17.2 (linux-zen), the device is detected, > but dmesg shows: > > usb 3-2: Presonus Studio 1810c, device_setup: 1 > usb 3-2: (8out/18in @ 48kHz) > usb 3-2: Quirk or no altset; falling back to MIDI 1.0 Have you tried 6.18-rc1? There have been already a few commits to support 1824c. Takashi > > The device works as a generic USB Audio interface, but: > - There are no hardware mixer/volume controls in `alsamixer` > - The driver cannot switch to 48 kHz mode (it defaults to 88.2/96 kHz) > - The proprietary control interface seems missing > > After investigating with `lsusb -v -d 194f:010d`, I found that firmware 3.11 > changes > the USB descriptor layout. The older firmware (probably 3.05) had a > vendor-specific (Application Specific) > interface used for the Presonus mixer quirk. The new firmware has **no > vendor-specific interface** > other than the DFU (firmware update) one. > > Excerpt from the descriptor: > > bInterfaceNumber 3 > bInterfaceClass 1 Audio > bInterfaceSubClass 1 Control Device > iInterface 0 > ... > bInterfaceNumber 5 > bInterfaceClass 254 Application Specific Interface > bInterfaceSubClass 1 Device Firmware Update > iInterface 12 PreSonus DFU > > It seems the firmware replaced the previous vendor mixer interface with an > additional > Audio Control interface (class 1, subclass 1). As a result, `mixer_s1810c.c` > does not > detect it and falls back to plain USB Audio + MIDI 1.0. > > **Device info:** > - Vendor ID: 0x194f > - Product ID: 0x010d (Studio 1824c) > - Firmware version: 3.11 > - Kernel version tested: 6.17.2 (zen) > - Distribution: Artix > - ALSA version: from kernel 6.17 tree > > **Expected behavior:** > The driver should attach the PreSonus quirk code (`mixer_s1810c.c`) and expose > the > hardware mixer and sample rate controls. > > **Actual behavior:** > Driver does not find the vendor interface, prints “Quirk or no altset; falling > back to MIDI 1.0,” > and no mixer controls appear. > > **Steps to reproduce:** > 1. Connect Studio 1824c with firmware 3.11 > 2. Check `dmesg` for the log above > 3. Observe missing controls in `alsamixer` > > **Attachments:** > - Full output of `lsusb -v -d 194f:010d` (firmware 3.11) > - `dmesg` excerpt from device plug-in > > **Suggestion:** > The driver might need to accept a second Audio Control interface as the mixer > interface > for new firmware revisions, since the vendor-specific interface seems to have > been replaced. > > I’m happy to provide full descriptors and test any experimental patch. > > Thank you for maintaining ALSA and the USB audio stack! > Best regards, > Pawel Piatek > xj@wp.pl > > [ +2,427945] usb 3-2: new high-speed USB device number 3 using xhci_hcd > [ +0,125645] usb 3-2: New USB device found, idVendor=194f, idProduct=010d, bcdDevice= 3.11 > [ +0,000006] usb 3-2: New USB device strings: Mfr=1, Product=3, SerialNumber=2 > [ +0,000001] usb 3-2: Product: Studio 1824c > [ +0,000001] usb 3-2: Manufacturer: PreSonus > [ +0,000000] usb 3-2: SerialNumber: SC4E25040072 > [ +0,380876] usb 3-2: Presonus Studio 1810c, device_setup: 0 > [ +0,000006] usb 3-2: (8out/14in @ 96kHz) > [ +0,440551] usb 3-2: Quirk or no altset; falling back to MIDI 1.0 > > Bus 003 Device 002: ID 194f:010d PreSonus Audio Electronics, Inc. Studio 1824c > Negotiated speed: High Speed (480Mbps) > Device Descriptor: > bLength 18 > bDescriptorType 1 > bcdUSB 2.00 > bDeviceClass 239 Miscellaneous Device > bDeviceSubClass 2 [unknown] > bDeviceProtocol 1 Interface Association > bMaxPacketSize0 64 > idVendor 0x194f PreSonus Audio Electronics, Inc. > idProduct 0x010d Studio 1824c > bcdDevice 3.11 > iManufacturer 1 PreSonus > iProduct 3 Studio 1824c > iSerial 2 SC4E25040072 > bNumConfigurations 1 > Configuration Descriptor: > bLength 9 > bDescriptorType 2 > wTotalLength 0x0281 > bNumInterfaces 6 > bConfigurationValue 1 > iConfiguration 0 > bmAttributes 0xc0 > Self Powered > MaxPower 0mA > Interface Association: > bLength 8 > bDescriptorType 11 > bFirstInterface 0 > bInterfaceCount 3 > bFunctionClass 1 Audio > bFunctionSubClass 0 [unknown] > bFunctionProtocol 32 > iFunction 0 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 0 > bAlternateSetting 0 > bNumEndpoints 1 > bInterfaceClass 1 Audio > bInterfaceSubClass 1 Control Device > bInterfaceProtocol 32 > iInterface 3 Studio 1824c > AudioControl Interface Descriptor: > bLength 9 > bDescriptorType 36 > bDescriptorSubtype 1 (HEADER) > bcdADC 2.00 > bCategory 8 > wTotalLength 0x00b7 > bmControls 0x00 > AudioControl Interface Descriptor: > bLength 8 > bDescriptorType 36 > bDescriptorSubtype 10 (CLOCK_SOURCE) > bClockID 41 > bmAttributes 3 Internal programmable clock > bmControls 0x03 > Clock Frequency Control (read/write) > bAssocTerminal 0 > iClockSource 9 Internal > AudioControl Interface Descriptor: > bLength 8 > bDescriptorType 36 > bDescriptorSubtype 10 (CLOCK_SOURCE) > bClockID 42 > bmAttributes 3 Internal programmable clock > bmControls 0x03 > Clock Frequency Control (read/write) > bAssocTerminal 0 > iClockSource 10 S/PDIF > AudioControl Interface Descriptor: > bLength 8 > bDescriptorType 36 > bDescriptorSubtype 10 (CLOCK_SOURCE) > bClockID 43 > bmAttributes 3 Internal programmable clock > bmControls 0x03 > Clock Frequency Control (read/write) > bAssocTerminal 0 > iClockSource 11 ADAT > AudioControl Interface Descriptor: > bLength 10 > bDescriptorType 36 > bDescriptorSubtype 11 (CLOCK_SELECTOR) > bClockID 40 > bNrInPins 3 > baCSourceID(0) 41 > baCSourceID(1) 42 > baCSourceID(2) 43 > bmControls 0x03 > Clock Selector Control (read/write) > iClockSelector 8 PreSonus Clock Selector > AudioControl Interface Descriptor: > bLength 17 > bDescriptorType 36 > bDescriptorSubtype 2 (INPUT_TERMINAL) > bTerminalID 2 > wTerminalType 0x0101 USB Streaming > bAssocTerminal 0 > bCSourceID 40 > bNrChannels 18 > bmChannelConfig 0x00000000 > iChannelNames 15 Line Out 1 (L) > bmControls 0x0000 > iTerminal 6 Studio 1824c > AudioControl Interface Descriptor: > bLength 12 > bDescriptorType 36 > bDescriptorSubtype 3 (OUTPUT_TERMINAL) > bTerminalID 20 > wTerminalType 0x0301 Speaker > bAssocTerminal 0 > bSourceID 2 > bCSourceID 40 > bmControls 0x0000 > iTerminal 0 > AudioControl Interface Descriptor: > bLength 17 > bDescriptorType 36 > bDescriptorSubtype 2 (INPUT_TERMINAL) > bTerminalID 1 > wTerminalType 0x0201 Microphone > bAssocTerminal 0 > bCSourceID 40 > bNrChannels 18 > bmChannelConfig 0x00000000 > iChannelNames 33 Mic/Inst/Line 1 > bmControls 0x0000 > iTerminal 0 > AudioControl Interface Descriptor: > bLength 82 > bDescriptorType 36 > bDescriptorSubtype 6 (FEATURE_UNIT) > bUnitID 11 > bSourceID 1 > bmaControls(0) 0x00000000 > bmaControls(1) 0x00000000 > bmaControls(2) 0x00000000 > bmaControls(3) 0x00000000 > bmaControls(4) 0x00000000 > bmaControls(5) 0x00000000 > bmaControls(6) 0x00000000 > bmaControls(7) 0x00000000 > bmaControls(8) 0x00000000 > bmaControls(9) 0x00000000 > bmaControls(10) 0x00000000 > bmaControls(11) 0x00000000 > bmaControls(12) 0x00000000 > bmaControls(13) 0x00000000 > bmaControls(14) 0x00000000 > bmaControls(15) 0x00000000 > bmaControls(16) 0x00000000 > bmaControls(17) 0x00000000 > bmaControls(18) 0x00000000 > iFeature 0 > AudioControl Interface Descriptor: > bLength 12 > bDescriptorType 36 > bDescriptorSubtype 3 (OUTPUT_TERMINAL) > bTerminalID 22 > wTerminalType 0x0101 USB Streaming > bAssocTerminal 0 > bSourceID 11 > bCSourceID 40 > bmControls 0x0000 > iTerminal 7 Studio 1824c > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x83 EP 3 IN > bmAttributes 3 > Transfer Type Interrupt > Synch Type None > Usage Type Data > wMaxPacketSize 0x0006 1x 6 bytes > bInterval 8 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 1 > bAlternateSetting 0 > bNumEndpoints 0 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 4 Studio 1824c > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 1 > bAlternateSetting 1 > bNumEndpoints 2 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 4 Studio 1824c > AudioStreaming Interface Descriptor: > bLength 16 > bDescriptorType 36 > bDescriptorSubtype 1 (AS_GENERAL) > bTerminalLink 2 > bmControls 0x05 > Active Alternate Setting Control (read-only) > Valid Alternate Setting Control (read-only) > bFormatType 1 > bmFormats 0x00000001 > PCM > bNrChannels 18 > bmChannelConfig 0x00000000 > iChannelNames 15 Line Out 1 (L) > AudioStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bSubslotSize 4 > bBitResolution 24 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x01 EP 1 OUT > bmAttributes 5 > Transfer Type Isochronous > Synch Type Asynchronous > Usage Type Data > wMaxPacketSize 0x01f8 1x 504 bytes > bInterval 1 > AudioStreaming Endpoint Descriptor: > bLength 8 > bDescriptorType 37 > bDescriptorSubtype 1 (EP_GENERAL) > bmAttributes 0x00 > bmControls 0x00 > bLockDelayUnits 2 Decoded PCM samples > wLockDelay 0x0008 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x81 EP 1 IN > bmAttributes 17 > Transfer Type Isochronous > Synch Type None > Usage Type Feedback > wMaxPacketSize 0x0004 1x 4 bytes > bInterval 4 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 1 > bAlternateSetting 2 > bNumEndpoints 2 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 4 Studio 1824c > AudioStreaming Interface Descriptor: > bLength 16 > bDescriptorType 36 > bDescriptorSubtype 1 (AS_GENERAL) > bTerminalLink 2 > bmControls 0x05 > Active Alternate Setting Control (read-only) > Valid Alternate Setting Control (read-only) > bFormatType 1 > bmFormats 0x00000001 > PCM > bNrChannels 14 > bmChannelConfig 0x00000000 > iChannelNames 15 Line Out 1 (L) > AudioStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bSubslotSize 4 > bBitResolution 24 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x01 EP 1 OUT > bmAttributes 5 > Transfer Type Isochronous > Synch Type Asynchronous > Usage Type Data > wMaxPacketSize 0x02d8 1x 728 bytes > bInterval 1 > AudioStreaming Endpoint Descriptor: > bLength 8 > bDescriptorType 37 > bDescriptorSubtype 1 (EP_GENERAL) > bmAttributes 0x00 > bmControls 0x00 > bLockDelayUnits 2 Decoded PCM samples > wLockDelay 0x0008 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x81 EP 1 IN > bmAttributes 17 > Transfer Type Isochronous > Synch Type None > Usage Type Feedback > wMaxPacketSize 0x0004 1x 4 bytes > bInterval 4 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 1 > bAlternateSetting 3 > bNumEndpoints 2 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 4 Studio 1824c > AudioStreaming Interface Descriptor: > bLength 16 > bDescriptorType 36 > bDescriptorSubtype 1 (AS_GENERAL) > bTerminalLink 2 > bmControls 0x05 > Active Alternate Setting Control (read-only) > Valid Alternate Setting Control (read-only) > bFormatType 1 > bmFormats 0x00000001 > PCM > bNrChannels 8 > bmChannelConfig 0x00000000 > iChannelNames 15 Line Out 1 (L) > AudioStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bSubslotSize 4 > bBitResolution 24 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x01 EP 1 OUT > bmAttributes 5 > Transfer Type Isochronous > Synch Type Asynchronous > Usage Type Data > wMaxPacketSize 0x0320 1x 800 bytes > bInterval 1 > AudioStreaming Endpoint Descriptor: > bLength 8 > bDescriptorType 37 > bDescriptorSubtype 1 (EP_GENERAL) > bmAttributes 0x00 > bmControls 0x00 > bLockDelayUnits 2 Decoded PCM samples > wLockDelay 0x0008 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x81 EP 1 IN > bmAttributes 17 > Transfer Type Isochronous > Synch Type None > Usage Type Feedback > wMaxPacketSize 0x0004 1x 4 bytes > bInterval 4 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 2 > bAlternateSetting 0 > bNumEndpoints 0 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 5 Studio 1824c > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 2 > bAlternateSetting 1 > bNumEndpoints 1 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 5 Studio 1824c > AudioStreaming Interface Descriptor: > bLength 16 > bDescriptorType 36 > bDescriptorSubtype 1 (AS_GENERAL) > bTerminalLink 22 > bmControls 0x05 > Active Alternate Setting Control (read-only) > Valid Alternate Setting Control (read-only) > bFormatType 1 > bmFormats 0x00000001 > PCM > bNrChannels 18 > bmChannelConfig 0x00000000 > iChannelNames 33 Mic/Inst/Line 1 > AudioStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bSubslotSize 4 > bBitResolution 24 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x82 EP 2 IN > bmAttributes 5 > Transfer Type Isochronous > Synch Type Asynchronous > Usage Type Data > wMaxPacketSize 0x01f8 1x 504 bytes > bInterval 1 > AudioStreaming Endpoint Descriptor: > bLength 8 > bDescriptorType 37 > bDescriptorSubtype 1 (EP_GENERAL) > bmAttributes 0x00 > bmControls 0x00 > bLockDelayUnits 2 Decoded PCM samples > wLockDelay 0x0008 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 2 > bAlternateSetting 2 > bNumEndpoints 1 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 5 Studio 1824c > AudioStreaming Interface Descriptor: > bLength 16 > bDescriptorType 36 > bDescriptorSubtype 1 (AS_GENERAL) > bTerminalLink 22 > bmControls 0x05 > Active Alternate Setting Control (read-only) > Valid Alternate Setting Control (read-only) > bFormatType 1 > bmFormats 0x00000001 > PCM > bNrChannels 14 > bmChannelConfig 0x00000000 > iChannelNames 33 Mic/Inst/Line 1 > AudioStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bSubslotSize 4 > bBitResolution 24 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x82 EP 2 IN > bmAttributes 5 > Transfer Type Isochronous > Synch Type Asynchronous > Usage Type Data > wMaxPacketSize 0x02d8 1x 728 bytes > bInterval 1 > AudioStreaming Endpoint Descriptor: > bLength 8 > bDescriptorType 37 > bDescriptorSubtype 1 (EP_GENERAL) > bmAttributes 0x00 > bmControls 0x00 > bLockDelayUnits 2 Decoded PCM samples > wLockDelay 0x0008 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 2 > bAlternateSetting 3 > bNumEndpoints 1 > bInterfaceClass 1 Audio > bInterfaceSubClass 2 Streaming > bInterfaceProtocol 32 > iInterface 5 Studio 1824c > AudioStreaming Interface Descriptor: > bLength 16 > bDescriptorType 36 > bDescriptorSubtype 1 (AS_GENERAL) > bTerminalLink 22 > bmControls 0x05 > Active Alternate Setting Control (read-only) > Valid Alternate Setting Control (read-only) > bFormatType 1 > bmFormats 0x00000001 > PCM > bNrChannels 8 > bmChannelConfig 0x00000000 > iChannelNames 33 Mic/Inst/Line 1 > AudioStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (FORMAT_TYPE) > bFormatType 1 (FORMAT_TYPE_I) > bSubslotSize 4 > bBitResolution 24 > Endpoint Descriptor: > bLength 7 > bDescriptorType 5 > bEndpointAddress 0x82 EP 2 IN > bmAttributes 5 > Transfer Type Isochronous > Synch Type Asynchronous > Usage Type Data > wMaxPacketSize 0x0320 1x 800 bytes > bInterval 1 > AudioStreaming Endpoint Descriptor: > bLength 8 > bDescriptorType 37 > bDescriptorSubtype 1 (EP_GENERAL) > bmAttributes 0x00 > bmControls 0x00 > bLockDelayUnits 2 Decoded PCM samples > wLockDelay 0x0008 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 3 > bAlternateSetting 0 > bNumEndpoints 0 > bInterfaceClass 1 Audio > bInterfaceSubClass 1 Control Device > bInterfaceProtocol 0 > iInterface 0 > AudioControl Interface Descriptor: > bLength 9 > bDescriptorType 36 > bDescriptorSubtype 1 (HEADER) > bcdADC 1.00 > wTotalLength 0x0009 > bInCollection 1 > baInterfaceNr(0) 1 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 4 > bAlternateSetting 0 > bNumEndpoints 2 > bInterfaceClass 1 Audio > bInterfaceSubClass 3 MIDI Streaming > bInterfaceProtocol 0 > iInterface 0 > MIDIStreaming Interface Descriptor: > bLength 7 > bDescriptorType 36 > bDescriptorSubtype 1 (HEADER) > bcdADC 1.00 > wTotalLength 0x0041 > MIDIStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (MIDI_IN_JACK) > bJackType 1 Embedded > bJackID 1 > iJack 0 > MIDIStreaming Interface Descriptor: > bLength 6 > bDescriptorType 36 > bDescriptorSubtype 2 (MIDI_IN_JACK) > bJackType 2 External > bJackID 2 > iJack 14 PreSonus MIDI In > MIDIStreaming Interface Descriptor: > bLength 9 > bDescriptorType 36 > bDescriptorSubtype 3 (MIDI_OUT_JACK) > bJackType 1 Embedded > bJackID 3 > bNrInputPins 1 > baSourceID( 0) 2 > BaSourcePin( 0) 1 > iJack 0 > MIDIStreaming Interface Descriptor: > bLength 9 > bDescriptorType 36 > bDescriptorSubtype 3 (MIDI_OUT_JACK) > bJackType 2 External > bJackID 4 > bNrInputPins 1 > baSourceID( 0) 1 > BaSourcePin( 0) 1 > iJack 13 PreSonus MIDI Out > Endpoint Descriptor: > bLength 9 > bDescriptorType 5 > bEndpointAddress 0x02 EP 2 OUT > bmAttributes 2 > Transfer Type Bulk > Synch Type None > Usage Type Data > wMaxPacketSize 0x0200 1x 512 bytes > bInterval 0 > bRefresh 0 > bSynchAddress 0 > MIDIStreaming Endpoint Descriptor: > bLength 5 > bDescriptorType 37 > bDescriptorSubtype 1 (Invalid) > bNumEmbMIDIJack 1 > baAssocJackID( 0) 1 > Endpoint Descriptor: > bLength 9 > bDescriptorType 5 > bEndpointAddress 0x84 EP 4 IN > bmAttributes 2 > Transfer Type Bulk > Synch Type None > Usage Type Data > wMaxPacketSize 0x0200 1x 512 bytes > bInterval 0 > bRefresh 0 > bSynchAddress 0 > MIDIStreaming Endpoint Descriptor: > bLength 5 > bDescriptorType 37 > bDescriptorSubtype 1 (Invalid) > bNumEmbMIDIJack 1 > baAssocJackID( 0) 3 > Interface Descriptor: > bLength 9 > bDescriptorType 4 > bInterfaceNumber 5 > bAlternateSetting 0 > bNumEndpoints 0 > bInterfaceClass 254 Application Specific Interface > bInterfaceSubClass 1 Device Firmware Update > bInterfaceProtocol 1 > iInterface 12 PreSonus DFU > Device Firmware Upgrade Interface Descriptor: > bLength 9 > bDescriptorType 33 > bmAttributes 7 > Will Not Detach > Manifestation Tolerant > Upload Supported > Download Supported > wDetachTimeout 250 milliseconds > wTransferSize 64 bytes > bcdDFUVersion 1.10 > Device Qualifier (for other device speed): > bLength 10 > bDescriptorType 6 > bcdUSB 2.00 > bDeviceClass 239 Miscellaneous Device > bDeviceSubClass 2 [unknown] > bDeviceProtocol 1 Interface Association > bMaxPacketSize0 64 > bNumConfigurations 1 > Device Status: 0x0001 > Self Powered