drm/amdgpu: Add runtime VCN PG support

Enable support for dynamically powering up/down VCN on demand.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 21 insertions, 11 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c b/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c
index dcb60ee0d9e2..110b294ebed3 100644
--- a/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/vcn_v1_0.c
@@ -35,7 +35,6 @@
 #include "mmhub/mmhub_9_1_offset.h"
 #include "mmhub/mmhub_9_1_sh_mask.h"
 
-static int vcn_v1_0_start(struct amdgpu_device *adev);
 static int vcn_v1_0_stop(struct amdgpu_device *adev);
 static void vcn_v1_0_set_dec_ring_funcs(struct amdgpu_device *adev);
 static void vcn_v1_0_set_enc_ring_funcs(struct amdgpu_device *adev);
@@ -146,10 +145,6 @@ static int vcn_v1_0_hw_init(void *handle)
         struct amdgpu_ring *ring = &adev->vcn.ring_dec;
         int i, r;
 
-        r = vcn_v1_0_start(adev);
-        if (r)
-                goto done;
-
         ring->ready = true;
         r = amdgpu_ring_test_ring(ring);
         if (r) {
@@ -185,11 +180,9 @@ static int vcn_v1_0_hw_fini(void *handle)
 {
         struct amdgpu_device *adev = (struct amdgpu_device *)handle;
         struct amdgpu_ring *ring = &adev->vcn.ring_dec;
-        int r;
 
-        r = vcn_v1_0_stop(adev);
-        if (r)
-                return r;
+        if (RREG32_SOC15(VCN, 0, mmUVD_STATUS))
+                vcn_v1_0_stop(adev);
 
         ring->ready = false;
 
@@ -769,7 +762,7 @@ static int vcn_v1_0_stop(struct amdgpu_device *adev)
         WREG32_P(SOC15_REG_OFFSET(UVD, 0, mmUVD_LMI_CTRL2), 0,
                         ~UVD_LMI_CTRL2__STALL_ARB_UMC_MASK);
 
-        /* enable clock gating */
+        WREG32_SOC15(VCN, 0, mmUVD_STATUS, 0);
 
         vcn_v1_0_enable_clock_gating(adev);
         vcn_1_0_enable_static_power_gating(adev);
@@ -1179,6 +1172,23 @@ static void vcn_v1_0_dec_ring_insert_nop(struct amdgpu_ring *ring, uint32_t coun
         }
 }
 
+static int vcn_v1_0_set_powergating_state(void *handle,
+                                          enum amd_powergating_state state)
+{
+        /* This doesn't actually powergate the VCN block.
+         * That's done in the dpm code via the SMC.  This
+         * just re-inits the block as necessary.  The actual
+         * gating still happens in the dpm code.  We should
+         * revisit this when there is a cleaner line between
+         * the smc and the hw blocks
+         */
+        struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+
+        if (state == AMD_PG_STATE_GATE)
+                return vcn_v1_0_stop(adev);
+        else
+                return vcn_v1_0_start(adev);
+}
 
 static const struct amd_ip_funcs vcn_v1_0_ip_funcs = {
         .name = "vcn_v1_0",
@@ -1197,7 +1207,7 @@ static const struct amd_ip_funcs vcn_v1_0_ip_funcs = {
         .soft_reset = NULL /* vcn_v1_0_soft_reset */,
         .post_soft_reset = NULL /* vcn_v1_0_post_soft_reset */,
         .set_clockgating_state = vcn_v1_0_set_clockgating_state,
-        .set_powergating_state = NULL /* vcn_v1_0_set_powergating_state */,
+        .set_powergating_state = vcn_v1_0_set_powergating_state,
 };
 
 static const struct amdgpu_ring_funcs vcn_v1_0_dec_ring_vm_funcs = {