"Fatal trap" when unloading usb2_controller_ehci

[Hans Petter Selasky]

Hi,

I don't think this is a USB problem. I rather think it has something to do  
with the IRQ handler. On my box the EHCI IRQ is shared with the IRQ of the 
graphics adapter, and when I unload the EHCI driver under X11 a couple of 
times X11 freezes. This does not happen on the console.

--HPS

On Sunday 08 February 2009, Bruce Cran wrote:
> Unloading usb2_controller_ehci is crashing FreeBSD on -CURRENT
> from a few days ago, resulting in a "Fatal trap" that isn't immediately
> fatal but ends up knocking out the rest of the system.
>
> Shortly after issuing a kldunload, the kernel drops into DDB with:
>
> Fatal trap 30: reserved (unknown) fault while in kernel mode
> cpuid = 0; apic id = 00
> instruction pointer = 0x8 : 0xffffffff804bc646
> stack pointer       = 0x10: 0xfffffffe40023b70
> frame pointer       = 0x10: 0xfffffffe40023b80
> code segment        = base 0x0, limit 0xfffff, type 0x1b
> processor eflags    = interrupt enabled, IOPL = 0
> current process     = 11 (idle : cpu0)
> [thread pid 11 tid 100004]
> Stopped at acpi_cpu_c1+0x6 : leave
>
> A backtrace just shows that the idle task was running at the time of
> the trap.  Attempting to continue results in a load of "calcru: runtime
> went backwards" messages followed by the ATA driver dying with:
>
> WARNING - SETFEATURES SET TRANSFER MODE taskqueue timeout - completing
> request directly
>
> Then follows similar messages about SET_MULTI, ENABLE RCACHE,
> ENABLE_WCACHE and WRITE_DMA48 etc.