Timing settings for graphics mode in D2550

[VAvul]

Hi,

The D2550 processor hangs when run in Linux frame buffer mode. After the graphics background has been drawn it freezes. It does not happen with N2600. There is no software difference between the two and they used the same VGA BIOS. The only difference is the graphics core speed of 640 MHz for D2550/N2800 and 400 MHz for N2600. That means that the D2500/N2800 needs different settings than N2600. The problem is that the VGA BIOS does not seem to know the difference between the CPUs and therefore sets the wrong timings which cause them to hang. The VGA BIOS therefore depends on the system BIOS to either setup the core frequency or tell the VGA BIOS the core frequency by initializing some registers.

How should the system BIOS interact with the VGA BIOS to help it to use the proper timings for the graphics modes?

How can the HDMI interface on Cedarview/NM10 be enabled via the BIOS?

Leads on the above issues will be very helpful. Thank you!

Best regards,

Vishnu

[WILLIAM_C_Intel]

Hi Vishnu,

Thanks for contacting us! Graphics Base frequency refers to the rated/guaranteed graphics render clock frequency in MHz, it is controled by processor hardware, instead of vBIOS.

About your D2550 processor hanging when run in Linux frame buffer mode, I have some questions.

1. Could you please tell me which Linux OS system have you installed?

2. Have you tried in another Linux mode? Such as text mode, graphic interface mode...

And you want to enable the HDMI interface in the BIOS. Please let me know which vbios and version do you use? GMA or IEMGD?

I am loking forward to your reply!

Best regards

William

[VAvul]

Hi William,

Thank you

Regarding HDMI:

We are using the GMA version of the VBIOS.

Regarding the Linux questions:

1) We have tried Debian, Ubuntu, Puppy, Yocto, Tiny Core. They don't crash on N2600 but crash on D2550.

2) All Linux versions above works in text mode.

Best regards,

Vishnu

[idata]

Hi Vishnu,

Thanks for reply!

About how to configure the HDMI on board the chipset, you can find the information about this on the Doc. ID 368119# http://pcache-www.intel.com/cd/00/00/36/81/368119_368119_GMA_BMP_UG_Rev3_1.pdf?HashKey=1392611923_4928f794c01528be5575de2b7f1eee11 http://pcache-www.intel.com/cd/00/00/36/81/368119_368119_GMA_BMP_UG_Rev3_1.pdf?HashKey=1392611923_4928f794c01528be5575de2b7f1eee11 Intel® Graphics Media Accelerator – Binary Modification Program (BMP) , Section 4.11, page 63, Integrated HDMI/ Display Port Configuration.

Regarding the Linux questions, I'm still searching for a sulotion, please be patient.

Best regards

William

[VAvul]

Hi William,

Thank you for pointing to the resourceful document addressing HDMI configuration.

Regarding the linux timing problem, here is more information, which we hope might help streamline your search:

We use the same VBIOS as used in Ami BIOS. With Ami BIOS it works with both the D2550 and N2600 boards. So we do have the proper VBIOS, but somehow the graphics mode crashes with D2550 with our BIOS. We suspect it has to do with the timings as the D2550 has higher frequency.

Maybe the VBIOS somehow doesn't understand that it's the faster graphics core when running under our BIOS. VBIOS thus using the timings for N2600 causing the crash due to the timings being too fast due to the higher speed graphics core frequency on the D2550 architecture.

So there is a dependency on system BIOS regarding the D2550 higher core frequency that we don't know about. The question is what it is? The VBIOS does not seem to be able to detect the graphics core without system BIOS help. So how do we help the VBIOS ?

Best regards,

Vishnu

[WILLIAM_C_Intel]

Hi Vishnu,

Thanks for your reply!

I discussed the situation with my colleagues, we highly suspect this issues is caused by system BIOS. Because AMI BIOS works well on your system.

So I would suggest you to contact your BIOS vendor to help you to resolve your BIOS's issues.

If there is anything else we can do for you, please let us know.

Best regards

William

[VAvul]

Hi William,

We are one of the system BIOS vendors and this timing issue is occurring in our BIOS. As mentioned earlier, we are unable to figure out the method to notify the VBIOS of the correct core frequency. So, information on how our system BIOS should communicate this information to the VBIOS solves the puzzle

Regarding HDMI configuration, the information on Doc. ID 442269# Intel® Graphics Media Accelerator – Video BIOS, Section 9.21, page 122, 5F54h – Hook to get Integrated EFP configuration from system BIOS refers to system BIOS populating the EFP child data structures. However, there is no information on the format of the EFP child structures.

Could you kindly help in this regard? Thank you!

Best regards,

Vishnu

[WILLIAM_C_Intel]

Hi Vishnu,

The system BIOS vendors should have proprietary technical support channels. It is recommended that you try to get technical support through other support window for the system BIOS vendors. If there is anything else we can do for you, please let us know.

Best regards

William

[VAvul]

Hi William,

We appreciate the assistance!

Could you please give more information about the proprietary technical support channel that you are referring to - so that we could avail their services.

Thanks & Regards,

Vishnu

[WILLIAM_C_Intel]

Hi Vishnu,

Fine, the http://www.intelintelligentsystemsalliance.com/solutions-directory?f[0]=field_processors_list:782 Intel® Intelligent Systems Alliance is a trusted supply line of Intel-based products and services where member companies offer solutions to speed development, design, and reduce costs. It provides the hardware, software, firmware, tools, and systems integration that developers need to take a leading role in the rise of intelligent systems. On the left side of the website you could find the system BIOS solutions.

Hope helps

Best regards

William

[WILLIAM_C_Intel]

Hi Vishnu,

Could you please tell us which system BIOS company are you from? And please give us the detailed information about your company, maybe we could find another support window for you. Thanks

Best regards

William

[VAvul]

Hi William,

That would be very helpful!

We at Winzent Technologies AB, Sweden develop system BIOS for Atom based platforms. We are a General Member of Intel Intelligent Systems Alliance. More information available at http://www.winzenttech.com/ http://www.winzenttech.com/

Thank you!

Best regards,

Vishnu

[Natalie_Z_Intel]

Hello, Vishnu! An Intel FAE may be able to help you. Feel free to contact him/her directly if you already know who the person is. Otherwise, we have also entered your info our system that will alert an Intel representative to contact you. I have also followed up with an email to that group along with the thread to this community conversation. I hope this added assistance will be beneficial to you!