On Thu, Dec 22, 2011 at 8:19 PM, James Simmons <jsimmons@xxxxxxxxxxxxx> wrote: > >> > Hi! >> > >> > I updated the openchrome tree and while testing on the AGP system >> > discovered some interesting problems with the new TTM changes. The >> > problems center around the ttm_tt_[un]populate which I modeled after the >> > radeon and nouveau driver. >> > First problem I noticed was on a AGP system that my ttm_tt_populate >> > function would oops. Tracking it down I found the problem was the >> > ttm_agp_tt_create calls ttm_tt_init instead of ttm_dma_tt_init so once my >> > ttm_tt_populate function would attempt to touch the dma_address it would >> > oops. The second issue is the assumption of the cast for struct ttm_tt in >> > both the populate and unpopulate function. For the AGP case the proper >> > case would be to ttm_agp_backend. >> > At this point my assumption is the ttm_bo_move function has to be >> > rewritten to handle the AGP case to avoid calling ttm_tt_bind and in all >> > cases ttm_tt_bind needs to be avoided. Looking at the radeon and nouveau >> > drivers I don't see that testing happening. Am I just missing something? >> >> Happens on AGP radeons as well: >> https://bugs.freedesktop.org/show_bug.cgi?id=43719 > > So I'm not crazy, so this needs to be fixed. Here is what my > understanding of the TTM layer is. My impression is that struct ttm_bo_driver > handles multiple domains, AGP, pcie etc and in each method you have to > handle each specific domain you support. Also *move gives the impression of > moving between these different domains. > Where as for struct ttm_backend_func was more for allocating from > a specific domain. Also I never saw a clear way to handle multiple backends. > For example my AGP systems can also do pci dma as well. Yes this need to be fixed, i am likely guilty, i tested agp along the way but i must have miss something. If no one beat me to it i will get back to this on january. Cheers, Jerome _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
