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Driver not reading EDID properly and denying correct values as custom resolution

Question asked by seneral on Feb 13, 2020

So this is a followup to a previous question after I managed to get it partly working.

In short:

Radeon Driver does not identify the specs of my LCD panel correctly (esp. timing), while CustomResolutionUtility does. The settings of CRU are correct, as verified on another PC on linux driving the LCD just fine out of the box.

Here are a few images illustrating the problem.

Trying to enter the correct timing values using the Custom Resolution tab results in radeon software saying they are not supported by the LCD. Again, this has been proven wrong meaning this is a bug.

With the incorrect timings, the driver actually adresses the display semi-correct, most of the time an actual image can be seen. However, visual glitches in the form of vertical lines can be consistently seen (vertical lines offset the pixels around 8 pixels upwards and these line glitches quickly jump between two adjacent pixel columns), in addition to the whole image flashing at varying frequencies (does not happen always) and a few other rarer differences (in short: it can be really random). These glitches have NOT been observed on the said other PC on linux, meaning the LCD is not faulty.

Thanks for any assistance! Hope this gets fixed, really depend on it to develop a product.

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