On Tue, Aug 14, 2018 at 09:29:26AM +0300, Ran Shalit wrote:
> On Mon, Aug 13, 2018 at 9:57 PM, Greg KH <gre...@linuxfoundation.org> wrote:
> > On Mon, Aug 13, 2018 at 09:34:37PM +0300, Ran Shalit wrote:
> >> Hello,
> >>
> >> I have a strange behabiour with sound card usb.
> >> I use kernel 3.18.11-rt7 (real-time kernel )
> >
> > Ugh, please go get support from whomever is forcing you to use such an
> > old and obsolete kernel version. You are paying them for support,
> > there's nothing that we can do about this :(
> >
> >> It takes 10 (!) seconds between detection of usb device till it is
> >> registered ("registered new interface driver snd-usb-audio") in
> >> kernel.
> >> We take the usb device out of reset using another HW.
> >>
> >> See below dmesg:
> >>
> >> [ 7.911220] ixgbe 0000:01:00.1: registered PHC device on eth1
> >> [ 8.186213] ixgbe 0000:01:00.1 eth1: NIC Link is Up 1 Gbps, Flow
> >> Control: RX/TX
> >> [ 8.218386] NET: Registered protocol family 10
> >> [ 8.691077] ixgbe 0000:01:00.0 eth0: NIC Link is Down
> >> [ 9.090808] ixgbe 0000:01:00.1 eth1: NIC Link is Down
> >> [ 9.893587] ixgbe 0000:01:00.0 eth0: NIC Link is Up 1 Gbps, Flow
> >> Control: RX/TX
> >> [ 10.317939] ixgbe 0000:01:00.1 eth1: NIC Link is Up 1 Gbps, Flow
> >> Control: RX/TX
> >> [ 38.171328] random: nonblocking pool is initialized
> >> [ 260.380461] usb 1-2: new full-speed USB device number 2 using xhci_hcd
> >> [ 260.545907] usb 1-2: config 1 has an invalid descriptor of length
> >> 0, skipping remainder of the config
> >> [ 260.546471] usb 1-2: New USB device found, idVendor=0451, idProduct=9010
> >> [ 260.546478] usb 1-2: New USB device strings: Mfr=1, Product=2,
> >> SerialNumber=3
> >> [ 260.546484] usb 1-2: Product: TI C55 Ver 6.00
> >> [ 260.546488] usb 1-2: Manufacturer: Texas Instruments
> >> [ 260.546491] usb 1-2: SerialNumber: 320001
> >> [ 260.594916] input: Texas Instruments TI C55 Ver 6.00 as
> >> /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.3/0003:0451:9010.0001/input/input3
> >> [ 260.595084] hid-generic 0003:0451:9010.0001: input,hidraw0: USB HID
> >> v1.11 Device [Texas Instruments TI C55 Ver 6.00] on
> >> usb-0000:00:14.0-2/input3
> >> [ 260.595153] usbcore: registered new interface driver usbhid
> >> [ 260.595157] usbhid: USB HID core driver
> >> [ 345.706843] usbcore: registered new interface driver snd-usb-audio
> >>
> >> Is there any idea what can cause this delay ?
> >
> > You are loading a new driver from somewhere, that takes time. Odds are
> > this is a userspace issue.
> >
> Thanks for the hint, which print did you refer to about the loading module ?
Your last one, that happens when the snd-usb-audio driver is loaded into
the kernel, it was not present before that. Go read up on how kernel
modules are automatically loaded when hardware is found, it's a long
kernel->userspace->kernel chain of events that happens.
> I will try to build the modules into kernel and see if it changes.
It will. But again, go bug the vendor that is forcing you to use such
an old ad obsolete kernel version for a new device please. That should
not be happening.
> We also noticed that in another kernel (and different ditribution too)
> the time is immediate, but it could be that the module was build
> inside kernel in that distribution. we also noticed that in the other
> distribution it is ehci_hcd, while in this (the slower) it is
> xhci_hcd. So that also might explain, right ?
No, the host controller driver should not matter at all.
good luck!
greg k-h
