1.6 Beta 2 with New i7 MBP screen flashes/flickers

frankhsueh · 04-26-2010, 01:27 AM

I couldn't find any fix to get the problem resolved. Same symptom happened on 1.5 and 1.6b1 and 1.6b2. That wasn't the case when I had my 1st generation Unibody MBP (5,1).

Carlo · 04-26-2010, 09:56 AM

Hi Frank,

Can you please use the tool at http://www.displaylink.com/support/ask_question.php
And let us have the logs? You can attach them here: http://www.displaylink.com/support/ask_question.php

Are the screens continuously flashing or they flash 'only' when the apps are started and closed? During the flashing is anything else happening (resolution change, windows moving, etc.)?

frankhsueh · 04-27-2010, 03:25 AM

Hi Carlo,

I have attached the log. There are total of 3 of them, from 1.5, 1.6b1 and 1.6b2. I've also included a link to youtube on the symptom I have.

http://www.youtube.com/watch?v=qyEqq4BNJ3s

Thanks

Carlo · 04-27-2010, 08:46 AM

Thank you so much Frank,

This is a high quality bug report!

It looks like this flash happens when Mac OS is switching GPU. And it's doing so when certain applications are opened, probably because they are linking frameworks that can benefit from the faster GPU.
If this is true this issue should only be visible on the new 15" and 17" MPB.

The symptom is not too bad luckily. The only hint in your logs is a WindowServer error, which is compatible with the fact that you're not seeing any kernel panic. And that the flash is on all screens. We'll start from there. And from getting a new MBP :-)

I have to warn you that we are working on other issues and improvements so I can't commit on a date for a fix.

frankhsueh · 04-27-2010, 04:09 PM

Hi Carlo,

I did some further testing and found your diagnosis to be correct. If I disable graphics auto switching to make it run on discrete GPU the whole time, the screens will not flash during launching/quitting applications.

04-26-2010, 09:56 AM	#2
Carlo Mac Team Join Date: Feb 2009 Posts: 606	Debug info please Hi Frank, Can you please use the tool at http://www.displaylink.com/support/ask_question.php And let us have the logs? You can attach them here: http://www.displaylink.com/support/ask_question.php Are the screens continuously flashing or they flash 'only' when the apps are started and closed? During the flashing is anything else happening (resolution change, windows moving, etc.)?

04-27-2010, 08:46 AM	#4
Carlo Mac Team Join Date: Feb 2009 Posts: 606	Switching GPU? Thank you so much Frank, This is a high quality bug report! It looks like this flash happens when Mac OS is switching GPU. And it's doing so when certain applications are opened, probably because they are linking frameworks that can benefit from the faster GPU. If this is true this issue should only be visible on the new 15" and 17" MPB. The symptom is not too bad luckily. The only hint in your logs is a WindowServer error, which is compatible with the fact that you're not seeing any kernel panic. And that the flash is on all screens. We'll start from there. And from getting a new MBP :-) I have to warn you that we are working on other issues and improvements so I can't commit on a date for a fix.

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04-26-2010, 01:27 AM	#1
frankhsueh Junior Member Join Date: Apr 2010 Posts: 4	I couldn't find any fix to get the problem resolved. Same symptom happened on 1.5 and 1.6b1 and 1.6b2. That wasn't the case when I had my 1st generation Unibody MBP (5,1).

04-27-2010, 04:09 PM	#5
frankhsueh Junior Member Join Date: Apr 2010 Posts: 4	Hi Carlo, I did some further testing and found your diagnosis to be correct. If I disable graphics auto switching to make it run on discrete GPU the whole time, the screens will not flash during launching/quitting applications.