drm/msm/adreno: Prevent unclocked access when retrieving timestamps

msm_gpu's get_timestamp() op (called by the MSM_GET_PARAM ioctl) can
result in register accesses. We need our power domain and clocks to
be active for that. Make sure they are enabled here.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -48,8 +48,15 @@ int adreno_get_param(struct msm_gpu *gpu, uint32_t param, uint64_t *value)
 		*value = adreno_gpu->base.fast_rate;
 		return 0;
 	case MSM_PARAM_TIMESTAMP:
-		if (adreno_gpu->funcs->get_timestamp)
-			return adreno_gpu->funcs->get_timestamp(gpu, value);
+		if (adreno_gpu->funcs->get_timestamp) {
+			int ret;
+
+			pm_runtime_get_sync(&gpu->pdev->dev);
+			ret = adreno_gpu->funcs->get_timestamp(gpu, value);
+			pm_runtime_put_autosuspend(&gpu->pdev->dev);
+
+			return ret;
+		}
 		return -EINVAL;
 	default:
 		DBG("%s: invalid param: %u", gpu->name, param);