drm/amd: Fix shutdown (again) on some SMU v13.0.4/11 platforms

commit cd94d1b ("dm/amd/pm: Fix problems with reboot/shutdown for
some SMU 13.0.4/13.0.11 users") attempted to fix shutdown issues
that were reported since commit 31729e8 ("drm/amd/pm: fixes a
random hang in S4 for SMU v13.0.4/11") but caused issues for some
people.

Adjust the workaround flow to properly only apply in the S4 case:
-> For shutdown go through SMU_MSG_PrepareMp1ForUnload
-> For S4 go through SMU_MSG_GfxDeviceDriverReset and
   SMU_MSG_PrepareMp1ForUnload

Reported-and-tested-by: lectrode <electrodexsnet@gmail.com>
Closes: void-linux/void-packages#50417
Cc: stable@vger.kernel.org
Fixes: cd94d1b ("dm/amd/pm: Fix problems with reboot/shutdown for some SMU 13.0.4/13.0.11 users")
Reviewed-by: Tim Huang <Tim.Huang@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: superm1

drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_4_ppt.c

@@ -226,15 +226,17 @@ static int smu_v13_0_4_system_features_control(struct smu_context *smu, bool en)
 	struct amdgpu_device *adev = smu->adev;
 	int ret = 0;
 
-	if (!en && adev->in_s4) {
-		/* Adds a GFX reset as workaround just before sending the
-		 * MP1_UNLOAD message to prevent GC/RLC/PMFW from entering
-		 * an invalid state.
-		 */
-		ret = smu_cmn_send_smc_msg_with_param(smu, SMU_MSG_GfxDeviceDriverReset,
-						      SMU_RESET_MODE_2, NULL);
-		if (ret)
-			return ret;
+	if (!en && !adev->in_s0ix) {
+		if (adev->in_s4) {
+			/* Adds a GFX reset as workaround just before sending the
+			 * MP1_UNLOAD message to prevent GC/RLC/PMFW from entering
+			 * an invalid state.
+			 */
+			ret = smu_cmn_send_smc_msg_with_param(smu, SMU_MSG_GfxDeviceDriverReset,
+							      SMU_RESET_MODE_2, NULL);
+			if (ret)
+				return ret;
+		}
 
 		ret = smu_cmn_send_smc_msg(smu, SMU_MSG_PrepareMp1ForUnload, NULL);
 	}