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IEGD 10.3.1 problem with NEC P-series panel on HDMI


Hi there, hoping you can help. Our environment is WES2009 running on an embedded industrial PC with GM45 graphics. There are three outputs: VGA, DVI and HDMI. In iEGD we configure them as Analog, sDVO-B and HDMI-C respectively. We disable monitor detection so that DVI is always monitor 1 and HDMI is monitor 2. (Don't use VGA). Running an extended desktop arrangement in Windows.

The screens we are using are NEC P-series such as P401, P461, P521.

Here is the problem: if we connect the hardware's HDMI output to the HDMI input of the panels, the resolution control in the driver properties is not working properly. It sort of works the 'first time', but after rebooting, the resolution drops back to 960x540, and if you change the resolution in the advanced IEGD config properties it drops back immediately you press apply, and has no effect. The Windows display properties are also stuck with the single resolution being 'available'.

I tried disabling EDID in the driver, and added manual DTD's, but this did not help.

Using other screens on HDMI I don't get this problem. I also don't get this problem driving the HDMI input of the NEC screen from the DVI output of the unit. This is effectively my workaround...I drive both screens using DVI inputs. In some ways this is better anyway because it gives me a level of consistent behavior between the two screens in their own setup, but nevertheless this is bugging me somewhat that I should have to do this.

Also, this problem does not arise with the desktop GMA drivers, and as I think I said it doesn't arise with other consumer desktop screens. I tried the 10.3.3 fix but that made no difference.

Given that the GMA drivers work, I think it must be either a config problem or a bug in the IEGD drivers. However I have tried every possible config setting in IEGD that looked relevant to no avail.

One interesting thing is that if I set the display config to Clone rather than DIH then both screens work fine.

What to do next?

Cheers, MT

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If you set a DTD, and configure the driver to ignore EDID, it should be at the resolution you set.

A couple of things could be going on here:

1. You are NOT configuring the driver to ignore the EDID properly and the monitor's EDID has some odd characteristics that cause the driver to pick the wrong mode- likely the display suggests the "best" mode which is not really the best mode.

2. The driver IS setting the desired resolution but you are looking at the on-screen display of the monitor for the resolution which is not always accurate. If you use the IEGD GUI, the mode shown there IS the mode the display is operating at despite what the monitor may think.

You might take a look at that and see what might be going on.

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