Hi,
I am getting these messages from a Debian 9.3 system using
Linux 4.9.x:
[ 547.352746] usb 3-5.2: 3:1: usb_set_interface failed (-28)
[ 548.352865] usb 3-5.3: Not enough bandwidth for new device state.
[ 548.352868] usb 3-5.3: Not enough bandwidth for altsetting 1
I have connected a 7-Port USB 3.0 Hub to my machine.
I have 6 different Headsets and USB Soundcards connected to the HUB.
As soon as I start a C++ application which opens all ALSA devices
I get these errors and the USB stopps working correctly.
I think the maximum count of USB sound devices, which behave stable
is three or four.
Is this some miscalculation of the Linux kernel regarding the USB
bandwidth usage? How I can determine how much bandwidth the USB
sound card driver preallocates?
Or are five USB soundcards really too much for an USB 3.0 bus?
Thanks in advance for any advise,
best regards
Waldemar
Hi,
Waldemar Brodkorb wrote,
> Hi,
>
> I am getting these messages from a Debian 9.3 system using
> Linux 4.9.x:
> [ 547.352746] usb 3-5.2: 3:1: usb_set_interface failed (-28)
> [ 548.352865] usb 3-5.3: Not enough bandwidth for new device state.
> [ 548.352868] usb 3-5.3: Not enough bandwidth for altsetting 1
>
> I have connected a 7-Port USB 3.0 Hub to my machine.
> I have 6 different Headsets and USB Soundcards connected to the HUB.
>
> As soon as I start a C++ application which opens all ALSA devices
> I get these errors and the USB stopps working correctly.
>
> I think the maximum count of USB sound devices, which behave stable
> is three or four.
>
> Is this some miscalculation of the Linux kernel regarding the USB
> bandwidth usage? How I can determine how much bandwidth the USB
> sound card driver preallocates?
>
> Or are five USB soundcards really too much for an USB 3.0 bus?
Adding some more information, which where missing in my first mail.
Attached are dmesg from the machine, lsusb verbose output and
aplay -l information.
There is no webcam involved, which usually uses MaxPacketsize of
1024,
so why I get the overallocation?
thanks, best regards
Waldemar