On Thu, 24 Jun 2010 21:51:40 +1200 Michael Cree <mcree@xxxxxxxxxxxx> wrote: > >> Is this a regression (what kernel version worked)? > >> > >> Seems that the IOMMU can't find 128 pages. It's likely due to: > >> > >> - out of the IOMMU space (possibly someone doesn't free the IOMMU > >> space). > >> > >> or > >> > >> - the mapping parameters (such as align) aren't appropriate so the > >> IOMMU can't find space. > > > > I don't think KMS drivers have ever worked on alpha so its not a > > regression, they are working fine on x86 + powerpc and sparc has been > > run at least once. > > KMS on the console boot up has worked since about 2.6.32, but starting > up the X server has always failed and, in my case, the system becomes > unstable and eventually OOPs. > > > I suspect we are simply hitting the limits of the iommu, how big an > > address space does it handle? since generally graphics drivers try to > > bind a lot of things to the GART. > > No idea on the address space limit. I applied the patch of Fujita that > logs all IOMMU allocations, and also inserted some extra printks in the > ttm kernel code so that I could see which routines failed and the error > code returned. Running the radeon test on boot exhibits the following: > > [ 238.712768] [drm] Tested GTT->VRAM and VRAM->GTT copy for GTT offset > 0x1a312000 > [ 239.281127] [drm] Tested GTT->VRAM and VRAM->GTT copy for GTT offset > 0x1a412000 > [ 239.281127] ttm_tt_bind belched -12 > [ 239.282104] ttm_bo_handle_move_mem belched -12 > [ 239.282104] ttm_bo_move_buffer belched -12 > [ 239.282104] ttm_bo_validate belched -12 > [ 239.282104] radeon 0000:01:00.0: object_init failed for (1048576, > 0x00000002) err=-12 > [ 239.282104] [drm:radeon_test_moves] *ERROR* Failed to create GTT > object 419 > [ 239.399291] Error while testing BO move. > > Note that no IOMMU allocations are printed while radeon_test_moves is > running so iommu_arena_alloc doesn't appear to be called. Also the > error code returned up to radeon_test_moves is -12 which is ENOMEM. So > does appear to be some memory limit. Hmm, not related with IOMMU? looks like ttm_tt_populate could return ENOMEM too. Can we locate where we hit ENOMEM first? -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
