drm/etnaviv: remove lastctx member from gpu struct

It only written and we don't infer any useful information from
it anymore. Remove it.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>

drivers/gpu/drm/etnaviv/etnaviv_buffer.c

@@ -439,6 +439,4 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, u32 exec_state,
 
 	if (drm_debug & DRM_UT_DRIVER)
 		etnaviv_buffer_dump(gpu, buffer, 0, 0x50);
-
-	gpu->lastctx = cmdbuf->ctx;
 }

drivers/gpu/drm/etnaviv/etnaviv_drv.c

@@ -72,14 +72,8 @@ static void etnaviv_postclose(struct drm_device *dev, struct drm_file *file)
 	for (i = 0; i < ETNA_MAX_PIPES; i++) {
 		struct etnaviv_gpu *gpu = priv->gpu[i];
 
-		if (gpu) {
-			mutex_lock(&gpu->lock);
-			if (gpu->lastctx == ctx)
-				gpu->lastctx = NULL;
-			mutex_unlock(&gpu->lock);
-
+		if (gpu)
 			drm_sched_entity_destroy(&ctx->sched_entity[i]);
-		}
 	}
 
 	kfree(ctx);

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -997,7 +997,6 @@ void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu)
 	spin_unlock(&gpu->event_spinlock);
 
 	etnaviv_gpu_hw_init(gpu);
-	gpu->lastctx = NULL;
 	gpu->exec_state = -1;
 
 	mutex_unlock(&gpu->lock);
@@ -1546,7 +1545,6 @@ static int etnaviv_gpu_hw_resume(struct etnaviv_gpu *gpu)
 	etnaviv_gpu_update_clock(gpu);
 	etnaviv_gpu_hw_init(gpu);
 
-	gpu->lastctx = NULL;
 	gpu->exec_state = -1;
 
 	mutex_unlock(&gpu->lock);

drivers/gpu/drm/etnaviv/etnaviv_gpu.h

@@ -97,7 +97,6 @@ struct etnaviv_gpu {
 	struct mutex lock;
 	struct etnaviv_chip_identity identity;
 	enum etnaviv_sec_mode sec_mode;
-	struct etnaviv_file_private *lastctx;
 	struct workqueue_struct *wq;
 	struct drm_gpu_scheduler sched;