On Thu, Jun 3, 2010 at 8:01 AM, Marek Vasut <marek.va...@gmail.com> wrote: > Dne Po 8. března 2010 13:16:35 Cyril Hrubis napsal(a): >> Hi! >> >> > - And I see display noise while CF Wi-Fi card is active. >> >> Forgotten about this one. See for yourself, notice short black vertical >> lines flashing randomly. >> >> http://atrey.karlin.mff.cuni.cz/~metan/outgoing/zaurus_sickness.mpg > > This is not only case of spitz. I've seen LCD image falling apart on pxafb on > Voipac PXA270 board. The image was like "torn in half and part of it was moved > to right, the hole between staying white". > > This happened exactly when I started doing a DMA transfer from a harddrive > attached through pata_pxa. It's perfectly replicable. If I disabled DMA and > let > it run only in PIO, the image was fine. > > I assume the corruption Pavel was seeing is related. My guess is the problems > are caused when DMA between the CPU and a companion chip happens. I dunno if > the > DMA controller doesn't have enough power to supply LCD and the companion chip > with data, but that's one of my guesses. > > btw. Adjusting the DMA descriptor length in pata_pxa didn't help. >
If there is a FIFO attached, may need the FIFO status when the error happens. And a dump of the DMA registers would also be helpful. _______________________________________________ Zaurus-devel mailing list Zaurus-devel@lists.linuxtogo.org http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/zaurus-devel