On Tue, Mar 20, 2012 at 9:40 AM, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > >> >> That is interesting! Are those patches published or otherwise available >> >> somewhere? We are also very interested in enabling Canyonlands >> >> with Radeon KMS! >> > >> > You will run into additional problems with 460 due to the fact that it's >> > not cache coherent for DMA. Tony patches don't address that part of the >> > problem (they were used on a 476 based platform). >> >> Hmm. Could you please spill a little bit more of details? Also are those patches >> for 476 merged or present somewhere? > > Well, DMA on 46x isn't cache coherent. The DRM plays interesting games > with mapping/unmapping pages for DMA by the chip and I don't think we > have the right hooks to do the appropriate cache flushing on these guys, > but Tony might be able to comment, I don't know whether he tried or not. > > On the other hand 476 has fully cache coherent DMA so the only problem > there is the >32-bit physical address space. > > As for the patches, you'll have to wait for Tony to respond (I'll poke > him locally). Any news on these patches? A dirty and "not for the upstream yet" version would be sufficient for me for now. > > Cheers, > Ben. > -- With best wishes Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
