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Video Bios setting to support eDP

KKhng
Beginner
3,353 Views

Hi Guys ,

I faced a display issue on Linux OS and got the feedback from the Linux expert as below ,

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

feedback from SuSE bugzilla on the findings:.

The root of this bug is in the video bios;

The connector type is reported as

display port. It should be embedded display port instead.

With eDP in video bios, the driver reads additional eDP link parameters, finds

out that only one lane should be used and this bug never happens.

To be more specific:

A device_type in Child Device Table block that describes the connector should

be changed from DP (0x68C6) to eDP (0x78C6).

The Truman machine I have here has VBT version 1.0 and BDB version 166. I

examined the dump made by the intel_bios_dump tool:

There are 8 Child Device Table blocks. Only the 4th of them has non-zero

device_type. The device_type is on addresses 0x0C9D-0x0C9E.

All that is needed is to change the byte at 0x0C9E from 0x68 to 0x78.

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But I try to change the Video Bios by latest Intel BMP tool , but i found that it had no selection for eDP (0xC678) as below,

Integrated HDMI/Display Port Configuration with External Connectors ->Device3 configuration ->Select Device Type

 

Selection:

 

No Device: ->0x0C9D-0X0C9E =00 00

 

Integrated Display Port Only: ->0x0C9D-0X0C9E =C6 68

 

Integrated Display Port with HDNI/DVI compatible: ->0x0C9D-0X0C9E =D6 60

 

Integrated Display Port with DVI compatible: ->0x0C9D-0X0C9E =D6 68

 

Integrated HDNI/DVI: ->0x0C9D-0X0C9E =D2 60

 

Integrated DVI Only: ->0x0C9D-0X0C9E =D2 68

Please help to advise .

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Kirk_B_Intel
Employee
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Hi,

You do not say what problem you are having, nor which processor/graphics generation you are using so it is a little difficult to see exactly what you are doing.

For some chipsets I definitely have seen an option to make the DP act like an eDP adding the additional steps for a device hooked to the DP channel but needed to be treated like an eDP device.

Once we know the issue and the specific chips, then we can help.

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