On Tue, Oct 15, 2013 at 09:46:18AM +0200, Sascha Hauer wrote: > 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? I tweaked it a different way - I used devmem2 to directly poke at the register. Inverting bit 17 (iow, clearing it) seems to fix the problem. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
