From: Takashi Iwai <tiwai@suse.de>
To: Pawel / Xj <xj@wp.pl>
Cc: linux-sound <linux-sound@vger.kernel.org>
Subject: Re: [BUG] Presonus Studio 1824c firmware 3.11 no longer exposes mixer interface ("Quirk or no altset; falling back to MIDI 1.0")
Date: Thu, 16 Oct 2025 12:53:04 +0200 [thread overview]
Message-ID: <874irz86en.wl-tiwai@suse.de> (raw)
In-Reply-To: <515e134e2b0a4364b6d595c77ef84216@grupawp.pl>
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
next prev parent reply other threads:[~2025-10-16 10:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-15 23:18 [BUG] Presonus Studio 1824c firmware 3.11 no longer exposes mixer interface ("Quirk or no altset; falling back to MIDI 1.0") Pawel / Xj
2025-10-16 10:53 ` Takashi Iwai [this message]
[not found] ` <bafec1e8819e47f1bea6e0bfa3f877cf@grupawp.pl>
2025-10-16 15:26 ` Takashi Iwai
2025-10-16 17:53 ` Xj
2025-10-16 20:21 ` Roy Vegard Ovesen
2025-10-17 2:36 ` Xj
2025-10-17 7:40 ` Takashi Iwai
2025-10-18 17:36 ` Roy Vegard Ovesen
2025-10-16 19:11 ` Roy Vegard Ovesen
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