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Warning: Mid-2009 MBP are incmpatible with certain USB 1.1 devices

Bob

Administrator
Staff member
I just came back from the apple store and report the following:
Certain USB 1.1 devices are incompatible with Mid-2009 Macbook Pros.

Devices that were found to be incompatible:
XRite i1 Pro rev B
Elinchrom usb EL-Skyport adapter Rev 1.3
The test was performed with the i1 pro at the local apple store.
Failed on both a 17 and 15 inch MBP OSX 10.5.7
OK on 2009 MP Nehelam and mid 2007 MP as well as mid 2007 15 inch MBP.
Tool used to demonstrate incompatibility: i1 diagnostics.
Reported to apple on 2009-06-28
Will call both xRite and Elincrom tomorrow.
thanks
-bob
 

Terry

New member
Bob, How can one tell what rev "number" i1 you have? I have one but haven't gotten to profile the 13" yet.
 

Bob

Administrator
Staff member
Turn it over, on the sticker mine indicated Rev B.
I am about 60% certain that this is an apple problem or baked into one of their chipsets.
-bob
 

Bob

Administrator
Staff member
Terry,
I didn't test a 13 inch model, but I would not be surprised to see a family resemblance.
-bob
 

Terry

New member
Well,
I haven't sent anything to print yet and my colors haven't looked hideous for posting so I think I have some time for it to get sorted out. But arrrghh :eek: none the less.
 
O

Oxide Blu

Guest
99.99% sure this is a USB2 oops, probably fixed with a future patch.

USB2 is supposed to be backward compatible. If Apple's USB ports aren't working, they aren't to USB spec ... so they aren't USB ports. They'll fix 'em.
 

Bob

Administrator
Staff member
Update 1:
The i1, although failing on both store and my own mid 2009 MBPs,, passed when the device was plugged into a powered hub which was then attached to the MBP.
At least for this device, it seems that the USB ports are under powered, or perhaps the device draws more than advertised,
In any case, with a powered hub, the i1 passes diagnostics and calibrates successfully.
-bob
 

Bob

Administrator
Staff member
Update 2:
I tested the skyport usb transceiver via the powered hub.
The skyport works.
The peculiar thing is that it works at the end of a powered hub even if the hub's external power source is removed.
When the hub is removed entirely, and the ukyport transceiver is connected directly to the same port on the MBP, it fails.

In the case of the skyport, I think that the behavior may be related to suspend mode current draw. The skyport presents a low power load (half a unit load) and the transient behavior of the connect to failure strongly implies a violation of USB 2.0 Link Power Management Engineering Change Notice. The resume function seems to not be functional after suspend when connected directly to the MBP, however it operates correctly when connected through even a bus powered hum.
I think the possible reason for this is that the MBP may be strictly enforcing the suspend mode current draw limitation which is proportional to device power draw. In this case that would require that the skyport use no more than 250 micro amps in suspended state, a power too easy to exceed. The MBP is then disconnecting the device during suspend mode (per spec). If the skyport were a high power device, it would have more to work with.
The hub represents a full low power usb load, compared to half a load for the skyport and it never suspends. thus is not disconnected.
The hub is more tolerant of suspend power draw, and simply provides the power without penalizing the device
Anyway, that is my theory in the case of the skyport.
 
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