drm/etnaviv: exec and MMU state is lost when resetting the GPU

When the GPU is reset both the current exec state, as well as all MMU
state is lost. Move the driver side state tracking into the reset function
to keep hardware and software state from diverging.

Cc: stable@vger.kernel.org # 5.4
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Michael Walle <michael@walle.cc>
Tested-by: Marek Vasut <marex@denx.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -570,6 +570,8 @@ static int etnaviv_hw_reset(struct etnaviv_gpu *gpu)
 	etnaviv_gpu_update_clock(gpu);
 
 	gpu->fe_running = false;
+	gpu->exec_state = -1;
+	gpu->mmu_context = NULL;
 
 	return 0;
 }
@@ -836,7 +838,6 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu)
 	/* Now program the hardware */
 	mutex_lock(&gpu->lock);
 	etnaviv_gpu_hw_init(gpu);
-	gpu->exec_state = -1;
 	mutex_unlock(&gpu->lock);
 
 	pm_runtime_mark_last_busy(gpu->dev);
@@ -1061,8 +1062,6 @@ void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu)
 	spin_unlock(&gpu->event_spinlock);
 
 	etnaviv_gpu_hw_init(gpu);
-	gpu->exec_state = -1;
-	gpu->mmu_context = NULL;
 
 	mutex_unlock(&gpu->lock);
 	pm_runtime_mark_last_busy(gpu->dev);