diff --git a/drivers/gpu/drm/radeon/si_dpm.c b/drivers/gpu/drm/radeon/si_dpm.c
index 91bfc4762767..918609551804 100644
--- a/drivers/gpu/drm/radeon/si_dpm.c
+++ b/drivers/gpu/drm/radeon/si_dpm.c
@@ -5250,10 +5250,9 @@ static int si_upload_sw_state(struct radeon_device *rdev,
 	int ret;
 	u32 address = si_pi->state_table_start +
 		offsetof(SISLANDS_SMC_STATETABLE, driverState);
-	u32 state_size = sizeof(SISLANDS_SMC_SWSTATE) +
-		((new_state->performance_level_count - 1) *
-		 sizeof(SISLANDS_SMC_HW_PERFORMANCE_LEVEL));
 	SISLANDS_SMC_SWSTATE *smc_state = &si_pi->smc_statetable.driverState;
+	size_t state_size = struct_size(smc_state, levels,
+					new_state->performance_level_count);
 
 	memset(smc_state, 0, state_size);
 
diff --git a/drivers/gpu/drm/radeon/sislands_smc.h b/drivers/gpu/drm/radeon/sislands_smc.h
index 966e3a556011..fbd6589bdab9 100644
--- a/drivers/gpu/drm/radeon/sislands_smc.h
+++ b/drivers/gpu/drm/radeon/sislands_smc.h
@@ -182,11 +182,11 @@ typedef struct SISLANDS_SMC_HW_PERFORMANCE_LEVEL SISLANDS_SMC_HW_PERFORMANCE_LEV
 
 struct SISLANDS_SMC_SWSTATE
 {
-    uint8_t                             flags;
-    uint8_t                             levelCount;
-    uint8_t                             padding2;
-    uint8_t                             padding3;
-    SISLANDS_SMC_HW_PERFORMANCE_LEVEL   levels[1];
+	uint8_t                             flags;
+	uint8_t                             levelCount;
+	uint8_t                             padding2;
+	uint8_t                             padding3;
+	SISLANDS_SMC_HW_PERFORMANCE_LEVEL   levels[];
 };
 
 typedef struct SISLANDS_SMC_SWSTATE SISLANDS_SMC_SWSTATE;