On Friday 11 June 2021 14:38:18 Christian König wrote: > > Am 10.06.21 um 19:59 schrieb Christian König: > > Am 10.06.21 um 19:50 schrieb Ondrej Zary: > >> [SNIP] > >>> I can't see how this is called from the nouveau code, only > >>> possibility I > >>> see is that it is maybe called through the AGP code somehow. > >> Yes, you're right: > >> [ 13.192663] Call Trace: > >> [ 13.192678] dump_stack+0x54/0x68 > >> [ 13.192690] ttm_tt_init+0x11/0x8a [ttm] > >> [ 13.192699] ttm_agp_tt_create+0x39/0x51 [ttm] > >> [ 13.192840] nouveau_ttm_tt_create+0x17/0x22 [nouveau] > >> [ 13.192856] ttm_tt_create+0x78/0x8c [ttm] > >> [ 13.192864] ttm_bo_handle_move_mem+0x7d/0xca [ttm] > >> [ 13.192873] ttm_bo_validate+0x92/0xc8 [ttm] > >> [ 13.192883] ttm_bo_init_reserved+0x216/0x243 [ttm] > >> [ 13.192892] ttm_bo_init+0x45/0x65 [ttm] > >> [ 13.193018] ? nouveau_bo_del_io_reserve_lru+0x48/0x48 [nouveau] > >> [ 13.193150] nouveau_bo_init+0x8c/0x94 [nouveau] > >> [ 13.193273] ? nouveau_bo_del_io_reserve_lru+0x48/0x48 [nouveau] > >> [ 13.193407] nouveau_bo_new+0x44/0x57 [nouveau] > >> [ 13.193537] nouveau_channel_prep+0xa3/0x269 [nouveau] > >> [ 13.193665] nouveau_channel_new+0x3c/0x5f7 [nouveau] > >> [ 13.193679] ? slab_free_freelist_hook+0x3b/0xa7 > >> [ 13.193686] ? kfree+0x9e/0x11a > >> [ 13.193781] ? nvif_object_sclass_put+0xd/0x16 [nouveau] > >> [ 13.193908] nouveau_drm_device_init+0x2e2/0x646 [nouveau] > >> [ 13.193924] ? pci_enable_device_flags+0x1e/0xac > >> [ 13.194052] nouveau_drm_probe+0xeb/0x188 [nouveau] > >> [ 13.194182] ? nouveau_drm_device_init+0x646/0x646 [nouveau] > >> [ 13.194195] pci_device_probe+0x89/0xe9 > >> [ 13.194205] really_probe+0x127/0x2a7 > >> [ 13.194212] driver_probe_device+0x5b/0x87 > >> [ 13.194219] device_driver_attach+0x2e/0x41 > >> [ 13.194226] __driver_attach+0x7c/0x83 > >> [ 13.194232] bus_for_each_dev+0x4c/0x66 > >> [ 13.194238] driver_attach+0x14/0x16 > >> [ 13.194244] ? device_driver_attach+0x41/0x41 > >> [ 13.194251] bus_add_driver+0xc5/0x16c > >> [ 13.194258] driver_register+0x87/0xb9 > >> [ 13.194265] __pci_register_driver+0x38/0x3b > >> [ 13.194271] ? 0xf0c0d000 > >> [ 13.194362] nouveau_drm_init+0x14c/0x1000 [nouveau] > >> > >> How is ttm_dma_tt->dma_address allocated? > > > > Mhm, I need to double check how AGP is supposed to work. > > > > Since barely anybody is using it these days it is something which > > breaks from time to time. > > I have no idea how that ever worked in the first place since AGP isn't > supposed to sync between CPU/GPU. Everything is coherent for that case. > > Anyway here is a patch which adds a check to those functions if the > dma_address array is allocated in the first place. Please test it. Thanks, the patch fixes the problem and nouveau now works! Should be applied to 5.12-stable too (5.11 is affected too but EOL). It's weird that it worked before. Looks like dma_address was used uninitialized - it contained some random crap: [ 12.293304] nouveau_bo_sync_for_device: ttm_dma->dma_address=3e055971 ttm_dma->ttm.num_pages=18 [ 12.293321] ttm_dma->dma_address[0]=0x0 [ 12.293341] ttm_dma->dma_address[1]=0x0 [ 12.293360] ttm_dma->dma_address[2]=0xee728980 [ 12.293379] ttm_dma->dma_address[3]=0xed1cb120 [ 12.293397] ttm_dma->dma_address[4]=0x12 [ 12.293416] ttm_dma->dma_address[5]=0x0 [ 12.293434] ttm_dma->dma_address[6]=0x1 [ 12.293453] ttm_dma->dma_address[7]=0x0 [ 12.293471] ttm_dma->dma_address[8]=0x10000 [ 12.293490] ttm_dma->dma_address[9]=0x0 [ 12.293510] ttm_dma->dma_address[10]=0x101 [ 12.293528] ttm_dma->dma_address[11]=0xee7289ec [ 12.293546] ttm_dma->dma_address[12]=0xee7289ec [ 12.293564] ttm_dma->dma_address[13]=0x0 [ 12.293581] ttm_dma->dma_address[14]=0x0 [ 12.293599] ttm_dma->dma_address[15]=0x0 [ 12.293616] ttm_dma->dma_address[16]=0x0 [ 12.293634] ttm_dma->dma_address[17]=0x0 But it did not matter as dma_sync_single_for_device is a no-op here. When dma_address is properly initialized to NULL, it crashes... > Thanks, > Christian. > > > > > Thanks for the backtrace, > > Christian. > > > >> I cannot find any assignment > >> executed (in the working code): > >> > >> $ git grep dma_address\ = drivers/gpu/ > >> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c: > >> sg->sgl->dma_address = addr; > >> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c: dma_address = > >> &dma->dma_address[offset >> PAGE_SHIFT]; > >> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c: dma_address = > >> (mm_node->start << PAGE_SHIFT) + offset; > >> drivers/gpu/drm/i915/gvt/scheduler.c: sg->dma_address = addr; > >> drivers/gpu/drm/i915/i915_gpu_error.c: sg->dma_address = it; > >> drivers/gpu/drm/ttm/ttm_tt.c: ttm->dma_address = (void *) > >> (ttm->ttm.pages + ttm->ttm.num_pages); > >> drivers/gpu/drm/ttm/ttm_tt.c: ttm->dma_address = > >> kvmalloc_array(ttm->ttm.num_pages, > >> drivers/gpu/drm/ttm/ttm_tt.c: ttm_dma->dma_address = NULL; > >> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c: viter->dma_address = > >> &__vmw_piter_phys_addr; > >> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c: viter->dma_address = > >> &__vmw_piter_dma_addr; > >> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c: viter->dma_address = > >> &__vmw_piter_sg_addr; > >> > >> The 2 cases in ttm_tt.c are in ttm_dma_tt_alloc_page_directory() and > >> ttm_sg_tt_alloc_page_directory(). > >> Confirmed by adding printk()s that they're NOT called. > >> > >> > > > > -- Ondrej Zary
