On Mon, Oct 14, 2013 at 11:50:29PM +0100, Russell King - ARM Linux wrote: > Answers to these two questions may help stop me wasting a lot of time > chasing what is a really weird bug. > > So, I have X up and running on the Cubox-i carrier-1, using the imx-drm > stuff (I've slightly hacked my xf86-armada X driver to get this working.) > This works fine - it detects the connectors, selects an appropriate > video mode and produces a picture of the correct shape and size. > > However... I see really weird effects colouring effects - almost like > water over the image. It's certain colour transitions in the image > which seem to trigger this. There are also certain pixels which > "twinkle". > > Text looks very strange too. Rather than the font being crisp and clear, > it looks like there's red and green shift to it - but its not that it's > all shifted in that way. > > Now, if I use the modetest utility from libdrm-2.4.43 to display a SMPTE > test pattern, this again looks right, but there are several vertical > single pixel lines of noise. The most striking one is below the upper > red bar in the lower dark area. I have a single pixel noisy vertical > line. > > I've tried the kernel which Rabeeh supplied, which is based on BSP 4.1.0, > and this works fine as far as I can tell with the same image (though, > it's a little difficult converting the XWD dump to something that can > be directly poked into /dev/fb0..., although this results in R/B swap.) > > Any ideas where to start looking? This sounds like the wrong clock polarity. Could you try inverting sig_cfg.clk_pol in imx-drm/ipuv3-crtc.c? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
