Hi All,

I have a 17" Apple Studio Display LCD that connects to a dual 1GHz 
quicksilver tower via ADC (on a GeForce 4 MX 440).  I am running 
-current from around August 2nd.  The dmesg lines look like this:

uhub2: Apple Computer product 0x9117, class 9/0, rev 1.10/1.10, addr 2
uhub2: 3 ports with 3 removable, self powered
uhidev3 at uhub2 port 3 configuration 1 interface 0
uhidev3: Apple Computer Studio Display, rev 1.00/2.0b, addr 3, iclass 3/0
uhidev3: 228 report ids
uhid0 at uhidev3 reportid 2: input=0, output=0, feature=257
uhid1 at uhidev3 reportid 16: input=0, output=0, feature=2
uhid2 at uhidev3 reportid 214: input=0, output=0, feature=2
uhid3 at uhidev3 reportid 228: input=2, output=0, feature=0

The monitor works great in X at 1280x1024.  The problem is that I can't 
figure out how to use usbhidctl to control the monitor's features. 
uhid0 seems to be information only; the other uhid devices seem to be 
what I actually want to change.  Here's what usbhidctl says:

hbent2# usbhidctl -f 1 -a
usbhidctl: USB_GET_REPORT(feature) [probably not supported by device]: 
Input/output error
hbent2# usbhidctl -f 1 -l -a
usbhidctl: Input report descriptor invalid length
hbent2# usbhidctl -f 1 -r
Report descriptor:
Feature size=8 count=1 page=VESA_Virtual_Controls usage=Brightness, 
logical range 0..255
Feature size=8 count=1 page=VESA_Virtual_Controls usage=Brightness, 
logical range 0..255
Total   input size 0 bytes
Total  output size 0 bytes
Total feature size 2 bytes

I have no idea how to use this information to adjust settings with 
usbhidctl, though.  I understand the -w syntax for normal USB devices, 
but I can't figure out how to change devices with features only.  Has 
anyone else managed to do this?  I'm sure I'm missing something simple, 
but it's just not striking me.  Thanks in advance.

-Henry Bent