Re: [BUG] Presonus Studio 1824c firmware 3.11 no longer exposes mixer interface ("Quirk or no altset; falling back to MIDI 1.0")

[Roy Vegard Ovesen <roy.vegard.ovesen@gmail.com>]

On Thu, Oct 16, 2025 at 07:53:23PM +0200, Xj wrote:
> 
> When I bought this card it has firmware 3.04, I upgraded it to 3.11.

I also have firmware 3.11. Unfortunately I don't remember what firmware
I had before 3.11, or if I noticed any difference.

> It works, but only in 88.2kHz and 96kHz modes and there is no volume control
> in alsamixer.

With kernel 6.18-rc1 it should work with all samplerates from 44.1k to 192k.
The (8out/14in @ 96kHz) output from the kernel is misleading (I will submit a
patch for that). It's from a quirk that is applied to the S1810c where it did
not handle having more than one altsetting for the playback and capture
interfaces. I don't own a S1810c, so I don't know all the details.

Anyways, my testing showed that the S1824c handled all 3 altsettings fine. And
when using Reaper or Ardour I am able to set the sample rate to anything from
44.1 to 192, and the number of ADAT channels is set according to the
appropriate altsetting.

I don't think I have ever seen any volume controls in alsamixer. I think
the only control I saw there before kernel version 6.15-rc1 was the clock
source selector. After 6.15-rc1, when the driver for th S1810c was applied
to the S1824c too, it added controls for the four buttons on the front
panel (48V, Line, Mute, A/B switch). The S1824c does not have a A/B switch
but a Mono button instead.

The S1824c has a comrehensive mixer with 2 x 36 x 9 = 648 individual volume
controls. To take full advantage of it you really need an application like
PreSonus Universal Control, but since they don't provide a linux version
I started creating baton (shameless plug):
[Link] https://github.com/royvegard/baton

> [    3.354758] ------------[ cut here ]------------
> [    3.354761] usb 3-2: BOGUS control dir, pipe 80000280 doesn't match bRequestType 40
> [    3.354769] WARNING: CPU: 12 PID: 1020 at drivers/usb/core/urb.c:412 usb_submit_urb+0x59f/0x650
> [    3.354776] Modules linked in:
> [    3.354779] CPU: 12 UID: 0 PID: 1020 Comm: alsactl Not tainted 6.18.0-rc1 #1 PREEMPT(full)  3ae07d8adb35c0aa13fd8a63520768d4d65cbe95
> [    3.354782] Hardware name: ASRock B850M Pro-A/B850M Pro-A, BIOS 3.50 09/18/2025
> [    3.354784] RIP: 0010:usb_submit_urb+0x59f/0x650
> [    3.354786] Code: 89 44 24 0c 89 4c 24 08 e8 5e 1f ef ff 44 8b 44 24 0c 8b 4c 24 08 48 c7 c7 c0 a5 15 b8 48 8b 54 24 18 48 89 c6 e8 f1 e9 b8 fe <0f> 0b 4c 8b 54 24 10 e9 fe fc ff ff 80 3d e9 83 4a 02 00 74 50 b8
> [    3.354788] RSP: 0018:ffffd1bdc23a3750 EFLAGS: 00010246
> [    3.354789] RAX: 0000000000000000 RBX: ffff8bc7c1facfc0 RCX: 00000000000003f9
> [    3.354790] RDX: 0000000000000000 RSI: ffffd1bdc23a35f0 RDI: 0000000000000003
> [    3.354791] RBP: ffff8bc7c6a0d058 R08: 0000000000000000 R09: 00000000ffffdfff
> [    3.354792] R10: ffffffffba11af80 R11: ffffd1bdc23a35e8 R12: 0000000000000000
> [    3.354793] R13: 0000000000000000 R14: ffff8bc7c6a0d000 R15: 0000000000000001
> [    3.354793] FS:  00007fab8f421b80(0000) GS:ffff8bcf24295000(0000) knlGS:0000000000000000
> [    3.354795] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    3.354795] CR2: 00007fab8f52c000 CR3: 0000000112652000 CR4: 0000000000f50ef0
> [    3.354796] PKRU: 55555554
> [    3.354797] Call Trace:
> [    3.354799]  <TASK>
> [    3.354801]  usb_start_wait_urb+0x89/0x190
> [    3.354804]  usb_control_msg+0xe5/0x150
> [    3.354806]  snd_usb_ctl_msg+0xa5/0x160
> [    3.354810]  snd_sc1810c_get_status_field.constprop.0+0xc0/0x140
> [    3.354815]  snd_s1810c_get_switch_state.constprop.0.isra.0+0x54/0xa0
> [    3.354817]  snd_s1810c_switch_set+0x69/0x130
> [    3.354820]  snd_ctl_elem_write+0x18b/0x260
> [    3.354824]  snd_ctl_ioctl+0x3b8/0x7e0
> [    3.354826]  __x64_sys_ioctl+0x97/0xe0
> [    3.354829]  do_syscall_64+0x81/0x7f0
> [    3.354833]  ? vfs_write+0x3c4/0x480
> [    3.354836]  ? ksys_write+0xbf/0xf0
> [    3.354837]  ? do_syscall_64+0x81/0x7f0
> [    3.354838]  ? __x64_sys_close+0x3d/0x80
> [    3.354840]  ? do_syscall_64+0x81/0x7f0
> [    3.354841]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [    3.354843] RIP: 0033:0x7fab8f3112ff
> [    3.354844] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 18 48 8b 44 24 18 64 48 2b 04 25 28 00 00
> [    3.354845] RSP: 002b:00007ffc8d758ca0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> [    3.354846] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fab8f3112ff
> [    3.354846] RDX: 00007ffc8d758e30 RSI: 00000000c4c85513 RDI: 0000000000000004
> [    3.354847] RBP: 00007ffc8d759480 R08: 00007ffc8d758e30 R09: 0000000000000000
> [    3.354847] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> [    3.354848] R13: 0000000000000003 R14: 0000000000000001 R15: 0000000000000001
> [    3.354848]  </TASK>
> [    3.354849] ---[ end trace 0000000000000000 ]---

This looks a bit sus.

-- 
Roy