drm/amd/amdgpu: fix the HDP LS/DS/SD programming

confirmed that IPH_MEM_POWER_CTRL_EN and RC_MEM_POWER_CTRL_EN
have to be set for SRAM LS/DS/SD
Signed-off-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/nv.c

@@ -889,6 +889,16 @@ static void nv_update_hdp_mem_power_gating(struct amdgpu_device *adev,
 						 RC_MEM_POWER_DS_EN, enable);
 	}
 
+	/* confirmed that IPH_MEM_POWER_CTRL_EN and RC_MEM_POWER_CTRL_EN have to
+	 * be set for SRAM LS/DS/SD */
+	if (adev->cg_flags & (AMD_CG_SUPPORT_HDP_LS | AMD_CG_SUPPORT_HDP_DS |
+							AMD_CG_SUPPORT_HDP_SD)) {
+		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl, HDP_MEM_POWER_CTRL,
+						IPH_MEM_POWER_CTRL_EN, 1);
+		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl, HDP_MEM_POWER_CTRL,
+						RC_MEM_POWER_CTRL_EN, 1);
+	}
+
 	WREG32_SOC15(HDP, 0, mmHDP_MEM_POWER_CTRL, hdp_mem_pwr_cntl);
 
 	/* restore IPH & RC clock override after clock/power mode changing */