drm/amdgpu: update HDP LS settings

Avoid unnecessary register programming on feature disablement.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/hdp_v5_0.c

@@ -90,45 +90,56 @@ static void hdp_v5_0_update_mem_power_gating(struct amdgpu_device *adev,
 					 RC_MEM_POWER_SD_EN, 0);
 	WREG32_SOC15(HDP, 0, mmHDP_MEM_POWER_CTRL, hdp_mem_pwr_cntl);
 
-	/* only one clock gating mode (LS/DS/SD) can be enabled */
-	if (adev->cg_flags & AMD_CG_SUPPORT_HDP_LS) {
-		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
-						 HDP_MEM_POWER_CTRL,
-						 IPH_MEM_POWER_LS_EN, enable);
-		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
-						 HDP_MEM_POWER_CTRL,
-						 RC_MEM_POWER_LS_EN, enable);
-	} else if (adev->cg_flags & AMD_CG_SUPPORT_HDP_DS) {
-		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
-						 HDP_MEM_POWER_CTRL,
-						 IPH_MEM_POWER_DS_EN, enable);
-		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
-						 HDP_MEM_POWER_CTRL,
-						 RC_MEM_POWER_DS_EN, enable);
-	} else if (adev->cg_flags & AMD_CG_SUPPORT_HDP_SD) {
-		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
-						 HDP_MEM_POWER_CTRL,
-						 IPH_MEM_POWER_SD_EN, enable);
-		/* RC should not use shut down mode, fallback to ds */
-		hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
-						 HDP_MEM_POWER_CTRL,
-						 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);
+	/* Already disabled above. The actions below are for "enabled" only */
+	if (enable) {
+		/* only one clock gating mode (LS/DS/SD) can be enabled */
+		if (adev->cg_flags & AMD_CG_SUPPORT_HDP_LS) {
+			hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+							 HDP_MEM_POWER_CTRL,
+							 IPH_MEM_POWER_LS_EN, 1);
+			hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+							 HDP_MEM_POWER_CTRL,
+							 RC_MEM_POWER_LS_EN, 1);
+		} else if (adev->cg_flags & AMD_CG_SUPPORT_HDP_DS) {
+			hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+							 HDP_MEM_POWER_CTRL,
+							 IPH_MEM_POWER_DS_EN, 1);
+			hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+							 HDP_MEM_POWER_CTRL,
+							 RC_MEM_POWER_DS_EN, 1);
+		} else if (adev->cg_flags & AMD_CG_SUPPORT_HDP_SD) {
+			hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+							 HDP_MEM_POWER_CTRL,
+							 IPH_MEM_POWER_SD_EN, 1);
+			/* RC should not use shut down mode, fallback to ds  or ls if allowed */
+			if (adev->cg_flags & AMD_CG_SUPPORT_HDP_DS)
+				hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+								 HDP_MEM_POWER_CTRL,
+								 RC_MEM_POWER_DS_EN, 1);
+			else if (adev->cg_flags & AMD_CG_SUPPORT_HDP_LS)
+				hdp_mem_pwr_cntl = REG_SET_FIELD(hdp_mem_pwr_cntl,
+								 HDP_MEM_POWER_CTRL,
+								 RC_MEM_POWER_LS_EN, 1);
+		}
+
+		/* 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);
+		}
 	}
 
-	WREG32_SOC15(HDP, 0, mmHDP_MEM_POWER_CTRL, hdp_mem_pwr_cntl);
-
-	/* restore IPH & RC clock override after clock/power mode changing */
-	WREG32_SOC15(HDP, 0, mmHDP_CLK_CNTL, hdp_clk_cntl1);
+	/* disable IPH & RC clock override after clock/power mode changing */
+	hdp_clk_cntl = REG_SET_FIELD(hdp_clk_cntl, HDP_CLK_CNTL,
+				     IPH_MEM_CLK_SOFT_OVERRIDE, 0);
+	hdp_clk_cntl = REG_SET_FIELD(hdp_clk_cntl, HDP_CLK_CNTL,
+				     RC_MEM_CLK_SOFT_OVERRIDE, 0);
+	WREG32_SOC15(HDP, 0, mmHDP_CLK_CNTL, hdp_clk_cntl);
 }
 
 static void hdp_v5_0_update_medium_grain_clock_gating(struct amdgpu_device *adev,