kernel panic with pure usb2umass pluged on pure usb1only motherboard port

[Hans Petter Selasky]

On Tuesday 06 September 2005 20:08, Mathieu PREVOT wrote:
> Hello,
>
> my kernel panics when I plug a pure USB2 umass. My motherboard has a
> VIA KT200 and has only USB1 ports.
> However, everything works perfectly with USB1 and USB1&2 umass.
> I used a custom kernel 5.4 but I noticed that behavior since 5.2.1. I
> not able to provide the output.
>
> Is it a known issue ?

There is one known bug in umass that will produce a panic on attach:

In "/sys/dev/usb/umass.c", maybe you can manually apply the following patch:

***************
*** 928,934 ****
  #endif
  
        if (sc->quirks & ALT_IFACE_1) {
!               err = usbd_set_interface(0, 1);
                if (err) {
                        DPRINTF(UDMASS_USB, ("%s: could not switch to "
                                "Alt Interface %d\n",
--- 929,935 ----
  #endif
  
        if (sc->quirks & ALT_IFACE_1) {
!               err = usbd_set_interface(uaa->iface, 1);
                if (err) {
                        DPRINTF(UDMASS_USB, ("%s: could not switch to "
                                "Alt Interface %d\n",

I am not sure if this is what is causing your panic.

But could you make sure that you have the following options in your kernel 
config file:

options         KDB                     # Enable kernel debugger support.
options         DDB                     # Support DDB.
options         GDB                     # Support remote GDB.

Then recompile the kernel, and then reproduce the panic. When the kernel 
enters the debugger. Type "backtrace". Write down the function names, not all 
the parameters, and post it.

--HPS