[PATCH] drm/amd/pm: fixes a random hang in S4 for SMU v13.0.4/11

[Tim Huang]

From: Tim Huang <tim.hu...@amd.com>

While doing multiple S4 stress tests, GC/RLC/PMFW get into
an invalid state resulting into hard hangs.

Adding a GFX reset as workaround just before sending the
MP1_UNLOAD message avoids this failure.

Signed-off-by: Tim Huang <tim.hu...@amd.com>
---
 drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_4_ppt.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_4_ppt.c 
b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_4_ppt.c
index e8119918ef6b..88f1a0d878f3 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_4_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_4_ppt.c
@@ -226,8 +226,18 @@ 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_s0ix)
+       if (!en && !adev->in_s0ix) {
+               /* 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);
+       }
 
        return ret;
 }
-- 
2.39.2