pci bus rescan from userland

[Yuri Pankov]

Ian Lepore wrote:
> On Sat, 2018-08-25 at 18:21 +0300, Yuri Pankov wrote:
>> Hi,
>>
>> Trying to enable the HDMI/DP sound output on NVIDIA Quadro M2200, I have
>> found the following workaround on NVIDIA Linux forums
>> (https://devtalk.nvidia.com/default/topic/1024022/linux/gtx-1060-no-audio-over-hdmi-only-hda-intel-detected-azalia/post/5211273/#5211273):
>>
>> setpci -s 01:00.0 0x488.l=0x2000000:0x2000000
>> rmmod nvidia-drm nvidia-modeset nvidia
>> echo 1 > /sys/bus/pci/devices/0000:01:00.0/remove
>> echo 1 > /sys/bus/pci/devices/0000:00:01.0/rescan
>> modprobe nvidia-drm
>>
>> So far rmmod and modprobe steps are obvious, setpci works as well (I
>> guess I could use pciconf? doesn't really matter).  Is there a FreeBSD
>> equivalent of doing the remove/rescan steps from userland?
> 
> devctl(8) has a rescan function.  devinfo(8) might be useful for
> figuring out which device(s) to use the rescan command on.
> 
> I don't know much about either of these tools beyond the fact that they
> exist.

Thanks, that did it (`devctl rescan pci1`), NVIDIA HDA controller now 
successfully attached.