Created attachment 118507 [details] dmesg file O.S: Ubuntu 14.10 Kernel 4.2 Intel Bay Trail I Using DP to LVDS converter CH7511B 1) There is signal on the monitor before entering to Operating System 2) There is signal on the monitor if using Windows 7 3) There is no signal on the monitor if using Ubuntu 14.10 -xrandr shows output disconnected -attached dmesg with drm.debug=0xe
Created attachment 118508 [details] VBIOS dump
Do you mean eDP to LVDS? Please try drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel
Hello Jani Thanks for your comments, the CH7511B has been configured as DP port, I will reply back as soon as possible with the results of the nightly branch. Best Regards, Adolfo.
Hello Jani We have tested with the latest build but the problem persist
Adolfo, from upstream perspective this is an out of the ordinary use case. If you want priority for this issue, please raise this with your usual support channels, referencing the bug. Thank you.
Hello Jani I'm not familiar with Bugzilla yet, I though I have set the Importance incorrectly the first time I opened the Bug report. I apologize for any inconvenience that I have caused for you.
Do you have a spec for the panel that the customer is using? Also, has the customer engaged with Chrontel about this issue? I notice that there is a EEPROM on the that needs to be programmed correctly with the EDID and some power-up timing / sequencing information that may need some different settings to work with Linux. Chrontel would be the best source of information / help on the EEPROM contents. Until we are sure that the EEPROM is being loaded with the correct information for Linux and for the specific panel the customer is using, any driver debug isn't likely to be very fruitful.
The customer sent me the ROM with the image of the CH7511B is that useful for you. I have requested more details about the programming, customer just changed the resolution using the Chrontel Programming Tool, so the rest of the configurations should be the default. In any case I will advice the customer to contact Chrontel for more information, is there any parameter that you are interested in? Thanks.
Hello Customer used the kernel parameter nomodeset, and used xserver instead of KMS now he is getting video output on the LVDS panel that is attached to CH7511B. Best Regards, Adolfo.
Fixed? Great news... but what was the fix?
Hello Jani On this case the customer didn't provide more feedback, the issue is fixed for the customer because he opted for using nomodeset and let the xserver handle the initialization. Is there any other status that would be more appropiate?
(In reply to Adolfo from comment #11) > Hello Jani > > On this case the customer didn't provide more feedback, the issue is fixed > for the customer because he opted for using nomodeset and let the xserver > handle the initialization. Is there any other status that would be more > appropiate? Thanks for the follow-up. I feel "fixed" is wrong because we didn't really fix anything. I'll choose wontfix. We can revisit that and reopen if needed, but I don't think we'll work on this anymore now.
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