On 24 April 2017 at 10:51, Christian König <deathsimple at vodafone.de> wrote: > Am 24.04.2017 um 11:42 schrieb Julien Isorce: > >> But re-add the flag is the bo is moved back to vram. >> >> This fixes "ring 0/3 stalled" issue which happens when the driver >> evicts bo from vram to gtt, at least on TAHITI and CAPVERDE. >> > > Interesting find, but NAK on the approach for fixing it. > Thx for the comments. > > If WC mappings don't work for TAHITI and CAPVERDE we need to figure out > why or at least disable them for those hardware generations in general. > Should I extend https://cgit.freedesktop.org/~agd5f/linux/tree/drivers/gpu/drm/radeon/radeon_object.c?h=amd-staging-4.9#n228 to BONAIRE (which will include VERDE and TAHITI) ? (to match https://cgit.freedesktop.org/~agd5f/linux/tree/drivers/gpu/drm/radeon/radeon_ib.c?h=amd-staging-4.9#n199 ) > > Disabling WC for BOs swapped out from VRAM won't buy us much if the BO was > initially created in GTT anyway. Initially created in VRAM: https://cgit.freedesktop.org/mesa/mesa/tree/src/gallium/drivers/radeon/r600_buffer_common.c#n164 > > > Christian. > > > >> I do not know the exact reason among the following: >> - si_copy_dma from vram to gtt is slow if WC >> (only for the non-visible part ? specific cases ?) >> - Allow snooping (SNOOPED flag from radeon_vm_bo_update). >> - WC should not be set at all for bo in the GTT >> (same reason why WC is only set for vram domain, >> see mesa::r600_init_resource_fields since mesa commit 5b6a0b7 >> "gallium/radeon: set GTT WC on tiled textures") >> - Bug in WC >> - Same reason as why radeon_sa_bo_manager_init is not passing >> WC flags if older than CHIP_BONAIRE (see 810b73d1 >> drm/radeon: Use write-combined CPU mappings of IBs on >= CIK) >> - Same as b738ca5d >> Revert "drm/radeon: Use write-combined CPU mappings of ring ..." >> - Same as 96ea47c0 >> drm/radeon: Disable uncacheable CPU mappings of GTT with RV6xx >> see https://bugs.freedesktop.org/show_bug.cgi?id=91268#c2 >> >> https://bugs.freedesktop.org/show_bug.cgi?id=100712 >> --- >> drivers/gpu/drm/radeon/radeon.h | 1 + >> drivers/gpu/drm/radeon/radeon_object.c | 1 + >> drivers/gpu/drm/radeon/radeon_ttm.c | 13 +++++++++++++ >> 3 files changed, 15 insertions(+) >> >> diff --git a/drivers/gpu/drm/radeon/radeon.h >> b/drivers/gpu/drm/radeon/radeon.h >> index 7a39a35..9847f4e 100644 >> --- a/drivers/gpu/drm/radeon/radeon.h >> +++ b/drivers/gpu/drm/radeon/radeon.h >> @@ -518,6 +518,7 @@ struct radeon_bo { >> struct radeon_mn *mn; >> struct list_head mn_list; >> + u32 vram_flags; >> }; >> #define gem_to_radeon_bo(gobj) container_of((gobj), struct radeon_bo, >> gem_base) >> diff --git a/drivers/gpu/drm/radeon/radeon_object.c >> b/drivers/gpu/drm/radeon/radeon_object.c >> index a557869..870f6b0 100644 >> --- a/drivers/gpu/drm/radeon/radeon_object.c >> +++ b/drivers/gpu/drm/radeon/radeon_object.c >> @@ -228,6 +228,7 @@ int radeon_bo_create(struct radeon_device *rdev, >> RADEON_GEM_DOMAIN_CPU); >> bo->flags = flags; >> + bo->vram_flags = 0; >> /* PCI GART is always snooped */ >> if (!(rdev->flags & RADEON_IS_PCIE)) >> bo->flags &= ~(RADEON_GEM_GTT_WC | RADEON_GEM_GTT_UC); >> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c >> b/drivers/gpu/drm/radeon/radeon_ttm.c >> index d07ff84..a8743bd 100644 >> --- a/drivers/gpu/drm/radeon/radeon_ttm.c >> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c >> @@ -440,6 +440,19 @@ static int radeon_bo_move(struct ttm_buffer_object >> *bo, >> r = radeon_move_ram_vram(bo, evict, interruptible, >> no_wait_gpu, new_mem); >> } else { >> + /* Clear WC flag when moving bo from vram to gtt. */ >> + if (old_mem->mem_type == TTM_PL_VRAM && new_mem->mem_type >> == TTM_PL_TT) { >> + if (rbo->flags & RADEON_GEM_GTT_WC) { >> + rbo->vram_flags |= RADEON_GEM_GTT_WC; >> + rbo->flags &= ~RADEON_GEM_GTT_WC; >> + } >> + /* Re-add WC flag when moving back from gtt to vram. */ >> + } else if (old_mem->mem_type == TTM_PL_TT && >> new_mem->mem_type == TTM_PL_VRAM) { >> + if (rbo->vram_flags & RADEON_GEM_GTT_WC) { >> + rbo->flags |= RADEON_GEM_GTT_WC; >> + rbo->vram_flags &= ~RADEON_GEM_GTT_WC; >> + } >> + } >> r = radeon_move_blit(bo, evict, no_wait_gpu, new_mem, >> old_mem); >> } >> >> > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20170424/b3aa5ed3/attachment.html>
