[PATCH v2] drm/amdgpu/sdma_v4_0: turn off SDMA ring buffer in the s2idle suspend

[Alex Deucher]

On Thu, Dec 1, 2022 at 2:56 AM Prike Liang <Prike.Liang at amd.com> wrote:
>
> In the SDMA s0ix save process requires to turn off SDMA ring buffer for
> avoiding the SDMA in-flight request, otherwise will suffer from SDMA page
> fault which causes by page request from in-flight SDMA ring accessing at
> SDMA restore phase.
>
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2248
> Cc: stable at vger.kernel.org # 6.0
> Fixes: f8f4e2a51834 ("drm/amdgpu: skipping SDMA hw_init and hw_fini for S0ix.")
>
> Signed-off-by: Prike Liang <Prike.Liang at amd.com>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
> -v2: change the name sdma_v4_0_gfx_stop() to sdma_v4_0_gfx_enable() (Lijo)
> ---
>  drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> index 1122bd4eae98..4d780e4430e7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
> @@ -907,13 +907,13 @@ static void sdma_v4_0_ring_emit_fence(struct amdgpu_ring *ring, u64 addr, u64 se
>
>
>  /**
> - * sdma_v4_0_gfx_stop - stop the gfx async dma engines
> + * sdma_v4_0_gfx_enable - enable the gfx async dma engines
>   *
>   * @adev: amdgpu_device pointer
> - *
> - * Stop the gfx async dma ring buffers (VEGA10).
> + * @enable: enable SDMA RB/IB
> + * control the gfx async dma ring buffers (VEGA10).
>   */
> -static void sdma_v4_0_gfx_stop(struct amdgpu_device *adev)
> +static void sdma_v4_0_gfx_enable(struct amdgpu_device *adev, bool enable)
>  {
>         u32 rb_cntl, ib_cntl;
>         int i;
> @@ -922,10 +922,10 @@ static void sdma_v4_0_gfx_stop(struct amdgpu_device *adev)
>
>         for (i = 0; i < adev->sdma.num_instances; i++) {
>                 rb_cntl = RREG32_SDMA(i, mmSDMA0_GFX_RB_CNTL);
> -               rb_cntl = REG_SET_FIELD(rb_cntl, SDMA0_GFX_RB_CNTL, RB_ENABLE, 0);
> +               rb_cntl = REG_SET_FIELD(rb_cntl, SDMA0_GFX_RB_CNTL, RB_ENABLE, enable ? 1 : 0);
>                 WREG32_SDMA(i, mmSDMA0_GFX_RB_CNTL, rb_cntl);
>                 ib_cntl = RREG32_SDMA(i, mmSDMA0_GFX_IB_CNTL);
> -               ib_cntl = REG_SET_FIELD(ib_cntl, SDMA0_GFX_IB_CNTL, IB_ENABLE, 0);
> +               ib_cntl = REG_SET_FIELD(ib_cntl, SDMA0_GFX_IB_CNTL, IB_ENABLE, enable ? 1 : 0);
>                 WREG32_SDMA(i, mmSDMA0_GFX_IB_CNTL, ib_cntl);
>         }
>  }
> @@ -1044,7 +1044,7 @@ static void sdma_v4_0_enable(struct amdgpu_device *adev, bool enable)
>         int i;
>
>         if (!enable) {
> -               sdma_v4_0_gfx_stop(adev);
> +               sdma_v4_0_gfx_enable(adev, enable);
>                 sdma_v4_0_rlc_stop(adev);
>                 if (adev->sdma.has_page_queue)
>                         sdma_v4_0_page_stop(adev);
> @@ -1960,8 +1960,10 @@ static int sdma_v4_0_suspend(void *handle)
>         struct amdgpu_device *adev = (struct amdgpu_device *)handle;
>
>         /* SMU saves SDMA state for us */
> -       if (adev->in_s0ix)
> +       if (adev->in_s0ix) {
> +               sdma_v4_0_gfx_enable(adev, false);
>                 return 0;
> +       }
>
>         return sdma_v4_0_hw_fini(adev);
>  }
> @@ -1971,8 +1973,12 @@ static int sdma_v4_0_resume(void *handle)
>         struct amdgpu_device *adev = (struct amdgpu_device *)handle;
>
>         /* SMU restores SDMA state for us */
> -       if (adev->in_s0ix)
> +       if (adev->in_s0ix) {
> +               sdma_v4_0_enable(adev, true);
> +               sdma_v4_0_gfx_enable(adev, true);
> +               amdgpu_ttm_set_buffer_funcs_status(adev, true);
>                 return 0;
> +       }
>
>         return sdma_v4_0_hw_init(adev);
>  }
> --
> 2.25.1
>