panic: resource_list_alloc: resource entry is busy

[Kevin Oberman]

On Fri, Sep 12, 2014 at 1:57 PM, Marcin Cieslak <saper at saper.info> wrote:

>
>
> On Fri, 12 Sep 2014, John Baldwin wrote:
>
>       at /usr/src/sys/dev/pci/vga_pci.c:318
>>> 318             return (bus_alloc_resource(dev, type, rid, start, end,
>>> count,
>>>
>> flags));
>>
>>> Current language:  auto; currently minimal
>>> (kgdb) p *rid
>>> $1 = 0
>>>
>>
>> Hmm, type 1 is SYS_RES_IRQ.  IRQ resources should not be marked reserved.
>>
>> Oh, some other child of vgapci has already allocated the IRQ.  That seems
>> odd.
>>
>> Can you get 'devinfo -r' output before you kldload i915kms and again after
>> doing the kldload?  (No need to run startx)
>>
>
> Please note I originally loaded "i915.ko", not "i915kms.ko"
>
>
> Unfortunately, "kldunload i915kms" makes my screen blank
> and probably crashes the system (disk activity stops after
> a short while and there is no response to the keyboard input).
>
> //Marcin
>
>
That explains most of it. You need i915kms. It is conflicting with i915
which already has  the IRQ allocated.

The black screen is expected. Once KMS starts talking to the graphics
system, syscons can no longer talk to the display, so you get a black
screen. To have a working display, you must enable vt(4). Add "kern.vty=vt"
to /boot/loader.conf to enable vt(4) which will keep the display alive.
--
R. Kevin Oberman, Network Engineer, Retired
E-mail: rkoberman at gmail.com