On Fri, Dec 23, 2011 at 01:19:43AM +0000, James Simmons 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.
> _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel Attached is patch to fix this, so sorry about that, i must have lost my agp change along the way when working on the patchset. This patch is not extensively tested, i will do more testing tomorrow on more gpu, might even found an nvidia agp i can try. Again sorry for breaking this. Cheers, Jerome
