> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Known issues

Qualcomm<sup>®</sup> Linux kernel known issues and their workarounds for the current release are listed below, organized by subsystem.

<Note>
  To see the current list of open issues and their status, see the [Qualcomm Linux release notes - Introduction](https://dragonwingdocs.qualcomm.com/Key-Documents/Software-Release-Notes/introduction).
</Note>

## **Kernel and boot**

**Table: Kernel and boot known issues**

| Issue                              | Description                                                                                                                       | Workaround                                                            |
| ---------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------- |
| First boot after flash may be slow | The first boot after flashing a new image may take longer than subsequent boots as the firmware performs one-time initialization. | Wait up to two minutes. The issue does not recur on subsequent boots. |

## **Real-time kernel**

**Table: Real-time kernel known issues**

| Issue                                | Description                                                                                                                 | Workaround                                                                                                                            |
| ------------------------------------ | --------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| High worst-case latency on first run | The first cyclictest run after boot may show elevated worst-case latency due to CPU frequency ramp-up and thermal settling. | Run the RT tuning script before the test and discard the first run's results. See [RT kernel fundamentals](./rt-kernel-fundamentals). |

## **Device tree**

**Table: Device tree known issues**

| Issue                             | Description                                                                                                       | Workaround                                                                                      |
| --------------------------------- | ----------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------- |
| DTB mismatch after kernel upgrade | Flashing a new kernel without updating the DTB partition can cause boot failures if new DT bindings are required. | Always flash the kernel and DTB together. See [Build and deploy DTBs](./build-and-deploy-dtbs). |

## **Report an issue**

To report a new issue, use the Qualcomm developer support portal or file a bug in the project tracker. Include the following information in the report:

* Kernel version: run `uname -r` on the target.
* Board and SoC: run `cat /proc/device-tree/compatible` on the target.
* Reproduction steps and the relevant `dmesg` output.