add the comments of the multi-device synchronization sample to set th…

…e kernel buffer

README.md

@@ -164,6 +164,25 @@ target_link_libraries(${PROJECT_NAME} OrbbecSDK::OrbbecSDK)
 * API Reference: [doc/api/English/index.html](https://orbbec.github.io/OrbbecSDK/doc/api/English/index.html)
 * OrbbecSDK C++ API user guide：[doc/tutorial/English/OrbbecSDK_C++_API_user_guide-v1.0.pdf](https://orbbec.github.io/OrbbecSDK/doc/tutorial/English/OrbbecSDK_C++_API_user_guide-v1.0.pdf)
 
+
+## Frequently Asked Questions
+
+### No Data Stream from Multiple Cameras
+
+**Insufficient Power Supply**:
+  - Ensure that all cameras are not connected to the same hub.
+  - Use a powered hub to provide sufficient power to each camera.
+
+**High Resolution**:
+  - Try lowering the resolution to resolve data stream issues.
+
+**Increase usbfs_memory_mb Value**:
+  - Increase the `usbfs_memory_mb` value to 128MB by running the following command:
+    ```bash
+    echo 128 | sudo tee /sys/module/usbcore/parameters/usbfs_memory_mb
+    ```
+  - For making this change permanent, check [this link](https://github.com/OpenKinect/libfreenect2/issues/807).
+
 ## Related links
 
 * [Orbbec SDK Repo](https://github.com/orbbec/OrbbecSDK)