drm/amdgpu/sdma_v4_0: turn off SDMA ring buffer in the s2idle suspend

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@vger.kernel.org # 6.0,5.15+
Fixes: f8f4e2a5 ("drm/amdgpu: skipping SDMA hw_init and hw_fini for S0ix.")
Signed-off-by: Prike Liang <Prike.Liang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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);
 }