Increase CONFIG_SND_MAX_CARDS?

Bome Products
23

I only had 8. I just tried adding an iCon I controls to the mix and it doesn’t show up.

Still testing …

24

Aha, yeah — that was the behavior. Did you get the error in the kernel log?

25

Yes,

[ 1886.690000] no available usb audio device
[ 1886.690000] snd-usb-audio: probe of 1-1.4:1.0 failed with error -5
[ 1896.730000] input: iCON iCON iControls V2.04 as /devices/platform/ehci-platform/usb1/1-1/1-1.4/1-1.4:1.1/input/input1
[ 1896.730000] hid-generic 0003:1D03:001A.0001: input,hidraw0: USB HID v1.10 Mouse [iCON iCON iControls V2.04] on usb-ehci-platform-1.4/input1

I’m going to try and load some Beta firmware on my BomeBox to see if it fixes it.

Steve Caldwell
Bome Customer Care

Also available for paid consulting services: bome@sniz.biz
26

Aha, yeah, it looks like CONFIG_SND_MAX_CARDS is 8 by default: https://elixir.bootlin.com/linux/v4.0/source/include/sound/core.h. I think it may take a custom kernel build to increase it beyond that.

27

OK, yes I’m now on Beta 1.5 and same problem (just different device not showing up). I’ll see what can be done and let you know.

Steve Caldwell
Bome Customer Care

Also available for paid consulting services: bome@sniz.biz
29

Hi, we have run tests with many devices (including multi-port devices), but there is a pending bug report of a user hitting a limit of, I think, 32 devices. We had not prioritized that bug, because 32 USB devices is plenty already. But 8 is definitely not enough!

I have just run a quick test with a USB 3 hub and indeed, I can confirm a maximum of 8 devices.

It could be an accidental reconfiguration in one of the last BomeBox firmware updates.
A bug report is filed.

30

Hi @florian

Just to be clear. If we have less than or equal to 8 physical USB devices, we are OK, even if there is more than 8 logical USB ports (within the physical devices). The issue is if there are more than 8 “physical” USB devices attached.

For instance, with 2 USB interfaces and 1 device (3 physical devices), it works fine even though 2 of the USB interfaces each have 4 logical devices ( 9 logical USB devices total).

I think the key question is how many physical USB devices should be realistically configured (maybe 16)?

Steve Caldwell
Bome Customer Care

Also available for paid consulting services: bome@sniz.biz
31

Yes, it seems that this is due to the linux kernel setting CONFIG_SND_DYNAMIC_MINORS . If it is not set, the kernel only allows 8 USB devices (no matter how many MIDI ports each device provides). If it’s set, we’re back to 32 USB devices.
I’ll run some tests tomorrow.

1 Like
32

Great — I thought this would have to be a regression, or it would have been mentioned in the docs. 32 devices would be great, and would be plenty of headroom.

33

No rush of course — I’m sure you’ve got a bunch of stuff to juggle, but when you get there, it’d be great to have a heads up on how long you think it’ll take to ship a fix, especially as we’re getting into the holidays (and I hope you’ll get some time off). If it’s going to be more than a week or two, I’ll either pick up a second box or some more midi interface ports so I can run off DIN for the time being.

34

I have a firmware build available which works with more than 8 USB devices here. I’ll PM you with a download link.

2 Likes