Or is the idea that we should never see a PDE fault unless something goes wrong, and that we would set up an entry corresponding to an unmapped subtree as an invalid PTE for a very large page rather than an invalid PDE? Thanks, John Original Message From: Bridgman, John Sent: Monday, February 25, 2019 22:46 To: Alex Deucher; Zhao, Yong Cc: amd-gfx list Subject: Re: [PATCH] drm/amdgpu: Set VM_L2_CNTL.PDE_FAULT_CLASSIFICATION to 0 Don't we want PDE faults to be treated the same way as page faults? Or am I misinterpreting the commit message? Thanks, John Original Message From: Alex Deucher Sent: Monday, February 25, 2019 21:53 To: Zhao, Yong Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx Subject: Re: [PATCH] drm/amdgpu: Set VM_L2_CNTL.PDE_FAULT_CLASSIFICATION to 0 On Mon, Feb 25, 2019 at 6:03 PM Zhao, Yong <Yong.Zhao@xxxxxxx> wrote: > > This is recommended by HW designers. Previously when it was set to 1, > the PDE walk error in VM fault will be treated as > PERMISSION_OR_INVALID_PAGE_FAULT rather than usually expected OTHER_FAULT. > As a result, the retry control in VM_CONTEXT*_CNTL will change accordingly. > > The above behavior is kind of abnormal. Furthermore, the > PDE_FAULT_CLASSIFICATION == 1 feature was targeted for very old ASICs > and it never made it way to production. Therefore, we should set it to 0. > > Signed-off-by: Yong Zhao <Yong.Zhao@xxxxxxx> Acked-by: Alex Deucher <alexander.deucher@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c | 2 +- > drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c b/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c > index f5edddf3b29d..c10ed568ca6c 100644 > --- a/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c > +++ b/drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c > @@ -143,7 +143,7 @@ static void gfxhub_v1_0_init_cache_regs(struct amdgpu_device *adev) > /* XXX for emulation, Refer to closed source code.*/ > tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, L2_PDE0_CACHE_TAG_GENERATION_MODE, > 0); > - tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, PDE_FAULT_CLASSIFICATION, 1); > + tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, PDE_FAULT_CLASSIFICATION, 0); > tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, CONTEXT1_IDENTITY_ACCESS_MODE, 1); > tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, IDENTITY_MODE_FRAGMENT_SIZE, 0); > WREG32_SOC15(GC, 0, mmVM_L2_CNTL, tmp); > diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c > index d0d966d6080a..2a039946a549 100644 > --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c > +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c > @@ -163,7 +163,7 @@ static void mmhub_v1_0_init_cache_regs(struct amdgpu_device *adev) > /* XXX for emulation, Refer to closed source code.*/ > tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, L2_PDE0_CACHE_TAG_GENERATION_MODE, > 0); > - tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, PDE_FAULT_CLASSIFICATION, 1); > + tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, PDE_FAULT_CLASSIFICATION, 0); > tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, CONTEXT1_IDENTITY_ACCESS_MODE, 1); > tmp = REG_SET_FIELD(tmp, VM_L2_CNTL, IDENTITY_MODE_FRAGMENT_SIZE, 0); > WREG32_SOC15(MMHUB, 0, mmVM_L2_CNTL, tmp); > -- > 2.17.1 > > _______________________________________________ > amd-gfx mailing list > amd-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/amd-gfx _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
