On my C4 (assumed to run factory NAND), it seems that u-boot sets the video mode to something equivalent to the following modeline:
1280x720@58 72 1280 1344 1394 1650 720 726 731 752
That configuration works perfectly on 2 of my DFP monitors.
Regarding HDTV's I tested, only two of three have been able to sync, but at the price of some frame dropped, and I am not happy with that.
I suspect a mismatch regarding standard VESA timings for 720p, those being at 60 or 50 Hz.
As for an example: "1280x720@60" 74,250 1280 1390 1430 1650 720 725 730 750
I am looking a way to fix:
* increase the pixel clock to standard 74,25Mhz for 720p@60 looks difficult if not impossible
* reduce pixel line length to catch VESA Hsync frequency (will it work on most of HDTV ?)
* Something else you could learn me
Does anybody experienced something similar, and found an acceptable solution ?