Hi Alex,
Is there anything open before it can be merged?
Thanks,
Haohui
On Mon, May 9, 2022 at 10:48 PM Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
>
> On Fri, May 6, 2022 at 10:30 PM Haohui Mai <ricetons@xxxxxxxxx> wrote:
> >
> > What about
> >
> > Setting the HALT bit of SDMA_F32_CNTL in all paths before programming
> > the ring buffer of the SDMA engine.
> >
>
> Sounds fine to me.
>
> Alex
>
> > No other changes are required in the patch.
> >
> > ~Haohui
> >
> > On Fri, May 6, 2022 at 9:36 PM Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
> > >
> > > On Fri, May 6, 2022 at 1:11 AM Haohui Mai <ricetons@xxxxxxxxx> wrote:
> > > >
> > > > The only thing that matters is that the IP should be halted before
> > > > programming the ring buffers.
> > > >
> > > > What about rephrasing the commit messages to highlight the issue a
> > > > little bit better?
> > >
> > > Yeah, that is fine. Thanks!
> > >
> > > Alex
> > >
> > > >
> > > > On Fri, May 6, 2022 at 12:33 AM Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
> > > > >
> > > > > On Sat, Apr 30, 2022 at 3:34 AM <ricetons@xxxxxxxxx> wrote:
> > > > > >
> > > > > > From: Haohui Mai <ricetons@xxxxxxxxx>
> > > > > >
> > > > > > The patch fully deactivates the DMA engine before setting up the ring
> > > > > > buffer to avoid potential data races and crashes.
> > > > >
> > > > > Does this actually fix an issue you are seeing? I don't think it will
> > > > > hurt anything, but I also don't think it's strictly necessary. AFAIK,
> > > > > only the HALT bit really matters. So the commit message might be
> > > > > somewhat misleading.
> > > > >
> > > > > Alex
> > > > >
> > > > > >
> > > > > > Signed-off-by: Haohui Mai <ricetons@xxxxxxxxx>
> > > > > > ---
> > > > > > drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c | 109 +++++++++++++++----------
> > > > > > 1 file changed, 64 insertions(+), 45 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c b/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c
> > > > > > index 013d2dec81d0..1fac9d8e99de 100644
> > > > > > --- a/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c
> > > > > > +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c
> > > > > > @@ -459,7 +459,6 @@ static void sdma_v5_2_ring_emit_fence(struct amdgpu_ring *ring, u64 addr, u64 se
> > > > > > }
> > > > > > }
> > > > > >
> > > > > > -
> > > > > > /**
> > > > > > * sdma_v5_2_gfx_stop - stop the gfx async dma engines
> > > > > > *
> > > > > > @@ -505,17 +504,21 @@ static void sdma_v5_2_rlc_stop(struct amdgpu_device *adev)
> > > > > > }
> > > > > >
> > > > > > /**
> > > > > > - * sdma_v5_2_ctx_switch_enable - stop the async dma engines context switch
> > > > > > + * sdma_v5_2_ctx_switch_enable_for_instance - start the async dma engines
> > > > > > + * context switch for an instance
> > > > > > *
> > > > > > * @adev: amdgpu_device pointer
> > > > > > - * @enable: enable/disable the DMA MEs context switch.
> > > > > > + * @instance_idx: the index of the SDMA instance
> > > > > > *
> > > > > > - * Halt or unhalt the async dma engines context switch.
> > > > > > + * Unhalt the async dma engines context switch.
> > > > > > */
> > > > > > -static void sdma_v5_2_ctx_switch_enable(struct amdgpu_device *adev, bool enable)
> > > > > > +static void sdma_v5_2_ctx_switch_enable_for_instance(struct amdgpu_device *adev, int instance_idx)
> > > > > > {
> > > > > > u32 f32_cntl, phase_quantum = 0;
> > > > > > - int i;
> > > > > > +
> > > > > > + if (WARN_ON(instance_idx >= adev->sdma.num_instances)) {
> > > > > > + return;
> > > > > > + }
> > > > > >
> > > > > > if (amdgpu_sdma_phase_quantum) {
> > > > > > unsigned value = amdgpu_sdma_phase_quantum;
> > > > > > @@ -539,50 +542,68 @@ static void sdma_v5_2_ctx_switch_enable(struct amdgpu_device *adev, bool enable)
> > > > > > phase_quantum =
> > > > > > value << SDMA0_PHASE0_QUANTUM__VALUE__SHIFT |
> > > > > > unit << SDMA0_PHASE0_QUANTUM__UNIT__SHIFT;
> > > > > > - }
> > > > > > -
> > > > > > - for (i = 0; i < adev->sdma.num_instances; i++) {
> > > > > > - if (enable && amdgpu_sdma_phase_quantum) {
> > > > > > - WREG32_SOC15_IP(GC, sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_PHASE0_QUANTUM),
> > > > > > - phase_quantum);
> > > > > > - WREG32_SOC15_IP(GC, sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_PHASE1_QUANTUM),
> > > > > > - phase_quantum);
> > > > > > - WREG32_SOC15_IP(GC, sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_PHASE2_QUANTUM),
> > > > > > - phase_quantum);
> > > > > > - }
> > > > > >
> > > > > > - if (!amdgpu_sriov_vf(adev)) {
> > > > > > - f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL));
> > > > > > - f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL,
> > > > > > - AUTO_CTXSW_ENABLE, enable ? 1 : 0);
> > > > > > - WREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL), f32_cntl);
> > > > > > - }
> > > > > > + WREG32_SOC15_IP(GC,
> > > > > > + sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_PHASE0_QUANTUM),
> > > > > > + phase_quantum);
> > > > > > + WREG32_SOC15_IP(GC,
> > > > > > + sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_PHASE1_QUANTUM),
> > > > > > + phase_quantum);
> > > > > > + WREG32_SOC15_IP(GC,
> > > > > > + sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_PHASE2_QUANTUM),
> > > > > > + phase_quantum);
> > > > > > }
> > > > > >
> > > > > > + if (!amdgpu_sriov_vf(adev)) {
> > > > > > + f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_CNTL));
> > > > > > + f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL,
> > > > > > + AUTO_CTXSW_ENABLE, 1);
> > > > > > + WREG32(sdma_v5_2_get_reg_offset(adev, instance_idx, mmSDMA0_CNTL), f32_cntl);
> > > > > > + }
> > > > > > }
> > > > > >
> > > > > > /**
> > > > > > - * sdma_v5_2_enable - stop the async dma engines
> > > > > > + * sdma_v5_2_ctx_switch_disable_all - stop the async dma engines context switch
> > > > > > *
> > > > > > * @adev: amdgpu_device pointer
> > > > > > - * @enable: enable/disable the DMA MEs.
> > > > > > *
> > > > > > - * Halt or unhalt the async dma engines.
> > > > > > + * Halt the async dma engines context switch.
> > > > > > */
> > > > > > -static void sdma_v5_2_enable(struct amdgpu_device *adev, bool enable)
> > > > > > +static void sdma_v5_2_ctx_switch_disable_all(struct amdgpu_device *adev)
> > > > > > {
> > > > > > u32 f32_cntl;
> > > > > > int i;
> > > > > >
> > > > > > - if (!enable) {
> > > > > > - sdma_v5_2_gfx_stop(adev);
> > > > > > - sdma_v5_2_rlc_stop(adev);
> > > > > > + if (amdgpu_sriov_vf(adev))
> > > > > > + return;
> > > > > > +
> > > > > > + for (i = 0; i < adev->sdma.num_instances; i++) {
> > > > > > + f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL));
> > > > > > + f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_CNTL,
> > > > > > + AUTO_CTXSW_ENABLE, 0);
> > > > > > + WREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_CNTL), f32_cntl);
> > > > > > }
> > > > > > +}
> > > > > > +
> > > > > > +/**
> > > > > > + * sdma_v5_2_halt - stop the async dma engines
> > > > > > + *
> > > > > > + * @adev: amdgpu_device pointer
> > > > > > + *
> > > > > > + * Halt the async dma engines.
> > > > > > + */
> > > > > > +static void sdma_v5_2_halt(struct amdgpu_device *adev)
> > > > > > +{
> > > > > > + int i;
> > > > > > + u32 f32_cntl;
> > > > > > +
> > > > > > + sdma_v5_2_gfx_stop(adev);
> > > > > > + sdma_v5_2_rlc_stop(adev);
> > > > > >
> > > > > > if (!amdgpu_sriov_vf(adev)) {
> > > > > > for (i = 0; i < adev->sdma.num_instances; i++) {
> > > > > > f32_cntl = RREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_F32_CNTL));
> > > > > > - f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_F32_CNTL, HALT, enable ? 0 : 1);
> > > > > > + f32_cntl = REG_SET_FIELD(f32_cntl, SDMA0_F32_CNTL, HALT, 1);
> > > > > > WREG32(sdma_v5_2_get_reg_offset(adev, i, mmSDMA0_F32_CNTL), f32_cntl);
> > > > > > }
> > > > > > }
> > > > > > @@ -594,6 +615,9 @@ static void sdma_v5_2_enable(struct amdgpu_device *adev, bool enable)
> > > > > > * @adev: amdgpu_device pointer
> > > > > > *
> > > > > > * Set up the gfx DMA ring buffers and enable them.
> > > > > > + * It assumes that the dma engine is stopped for each instance.
> > > > > > + * The function enables the engine and preemptions sequentially for each instance.
> > > > > > + *
> > > > > > * Returns 0 for success, error for failure.
> > > > > > */
> > > > > > static int sdma_v5_2_gfx_resume(struct amdgpu_device *adev)
> > > > > > @@ -737,10 +761,7 @@ static int sdma_v5_2_gfx_resume(struct amdgpu_device *adev)
> > > > > >
> > > > > > ring->sched.ready = true;
> > > > > >
> > > > > > - if (amdgpu_sriov_vf(adev)) { /* bare-metal sequence doesn't need below to lines */
> > > > > > - sdma_v5_2_ctx_switch_enable(adev, true);
> > > > > > - sdma_v5_2_enable(adev, true);
> > > > > > - }
> > > > > > + sdma_v5_2_ctx_switch_enable_for_instance(adev, i);
> > > > > >
> > > > > > r = amdgpu_ring_test_ring(ring);
> > > > > > if (r) {
> > > > > > @@ -784,7 +805,7 @@ static int sdma_v5_2_load_microcode(struct amdgpu_device *adev)
> > > > > > int i, j;
> > > > > >
> > > > > > /* halt the MEs */
> > > > > > - sdma_v5_2_enable(adev, false);
> > > > > > + sdma_v5_2_halt(adev);
> > > > > >
> > > > > > for (i = 0; i < adev->sdma.num_instances; i++) {
> > > > > > if (!adev->sdma.instance[i].fw)
> > > > > > @@ -856,8 +877,8 @@ static int sdma_v5_2_start(struct amdgpu_device *adev)
> > > > > > int r = 0;
> > > > > >
> > > > > > if (amdgpu_sriov_vf(adev)) {
> > > > > > - sdma_v5_2_ctx_switch_enable(adev, false);
> > > > > > - sdma_v5_2_enable(adev, false);
> > > > > > + sdma_v5_2_ctx_switch_disable_all(adev);
> > > > > > + sdma_v5_2_halt(adev);
> > > > > >
> > > > > > /* set RB registers */
> > > > > > r = sdma_v5_2_gfx_resume(adev);
> > > > > > @@ -881,12 +902,10 @@ static int sdma_v5_2_start(struct amdgpu_device *adev)
> > > > > > amdgpu_gfx_off_ctrl(adev, false);
> > > > > >
> > > > > > sdma_v5_2_soft_reset(adev);
> > > > > > - /* unhalt the MEs */
> > > > > > - sdma_v5_2_enable(adev, true);
> > > > > > - /* enable sdma ring preemption */
> > > > > > - sdma_v5_2_ctx_switch_enable(adev, true);
> > > > > >
> > > > > > - /* start the gfx rings and rlc compute queues */
> > > > > > + /* Soft reset supposes to disable the dma engine and preemption.
> > > > > > + * Now start the gfx rings and rlc compute queues.
> > > > > > + */
> > > > > > r = sdma_v5_2_gfx_resume(adev);
> > > > > > if (adev->in_s0ix)
> > > > > > amdgpu_gfx_off_ctrl(adev, true);
> > > > > > @@ -1340,8 +1359,8 @@ static int sdma_v5_2_hw_fini(void *handle)
> > > > > > if (amdgpu_sriov_vf(adev))
> > > > > > return 0;
> > > > > >
> > > > > > - sdma_v5_2_ctx_switch_enable(adev, false);
> > > > > > - sdma_v5_2_enable(adev, false);
> > > > > > + sdma_v5_2_ctx_switch_disable_all(adev);
> > > > > > + sdma_v5_2_halt(adev);
> > > > > >
> > > > > > return 0;
> > > > > > }
> > > > > > --
> > > > > > 2.25.1
> > > > > >
