> ## 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 and workarounds

<Note>
  This page documents **temporary** workarounds and known issues for Bluetooth
  on Qualcomm Linux. Each entry is expected to be removed once the proper fix
  lands in a release. Don't rely on the contents of this page for production
  deployments.
</Note>

## Workarounds

<a id="workarounds" />

### Change the Bluetooth chipset to QCC2072 on the Qualcomm Dragonwing IQ-9075 EVK

By default, the Dragonwing IQ-9075 EVK has the WCN6855 chipset software. To use the QCC2072, apply the following changes.

**Steps:**

1. Save the following patch with the filename `0001-dts-change-bt-from-wcn6855-to-qcc2072.patch`.

   ```patch expandable theme={null}
   Subject: [PATCH] linux-qcom-6.18: Replace wcn6855 with qcc2072

   Update the Bluetooth chip from wcn6855 to qcc2072
   ---
    ...emans-evk-Change-bluetooth-from-wcn6.patch | 28 +++++++++++++++++++
    recipes-kernel/linux/linux-qcom_6.18.bb       |  1 +
    2 files changed, 29 insertions(+)
    create mode 100644 recipes-kernel/linux/linux-qcom-6.18/0001-arm64-dts-qcom-lemans-evk-Change-bluetooth-from-wcn6.patch

   diff --git a/recipes-kernel/linux/linux-qcom-6.18/0001-arm64-dts-qcom-lemans-evk-Change-bluetooth-from-wcn6.patch b/recipes-kernel/linux/linux-qcom-6.18/0001-arm64-dts-qcom-lemans-evk-Change-bluetooth-from-wcn6.patch
   new file mode 100644
   index 00000000..8e5ac1b2
   --- /dev/null
   +++ b/recipes-kernel/linux/linux-qcom-6.18/0001-arm64-dts-qcom-lemans-evk-Change-bluetooth-from-wcn6.patch
   @@ -0,0 +1,28 @@

   +Subject: [PATCH] arm64: dts: qcom: lemans-evk: Replace wcn6855 with qcc2072
   +
   +Update the Bluetooth chip from wcn6855 to qcc2072.
   +
   +Upstream-Status: Pending
   +---
   + arch/arm64/boot/dts/qcom/lemans-evk.dts | 2 +-
   + 1 file changed, 1 insertion(+), 1 deletion(-)
   +
   +diff --git a/arch/arm64/boot/dts/qcom/lemans-evk.dts b/arch/arm64/boot/dts/qcom/lemans-evk.dts
   +index eec8b8a1d9ae..fc0b053f5c4b 100644
   +--- a/arch/arm64/boot/dts/qcom/lemans-evk.dts
   ++++ b/arch/arm64/boot/dts/qcom/lemans-evk.dts
   +@@ -1099,7 +1099,7 @@ &uart17 {
   + 	status = "okay";
   + 
   + 	bluetooth: bluetooth {
   +-		compatible = "qcom,wcn6855-bt";
   ++		compatible = "qcom,qcc2072-bt";
   + 		max-speed = <3200000>;
   + 
   + 		vddrfacmn-supply = <&vreg_wcn_3p3>;
   +-- 
   +2.34.1
   +
   diff --git a/recipes-kernel/linux/linux-qcom_6.18.bb b/recipes-kernel/linux/linux-qcom_6.18.bb
   index a1762ea5..82068146 100644
   --- a/recipes-kernel/linux/linux-qcom_6.18.bb
   +++ b/recipes-kernel/linux/linux-qcom_6.18.bb
   @@ -25,6 +25,7 @@ SRCBRANCH:class-devupstream ?= "branch=qcom-6.18.y"
    SRC_URI = " \
        git://github.com/qualcomm-linux/kernel.git;${SRCBRANCH};protocol=https \
        file://0001-tools-use-basename-to-identify-file-in-gen-mach-type.patch \
   +    file://0001-arm64-dts-qcom-lemans-evk-Change-bluetooth-from-wcn6.patch \
    "
    
    # Additional kernel configs.
   -- 
   2.34.1
   ```
2. Apply the patch to the `meta-qcom` tree.
3. Build and flash the image.
4. Push the following firmware files to the device. The files can be obtained from the [linux-firmware repository](https://web.git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/qca/).
   * `ornbcscal11.bin` → `/lib/firmware/qca/ornbcscal11.bin`
   * `ornbtfw11.tlv` → `/lib/firmware/qca/ornbtfw11.tlv`
   * `ornnv11.bin` → `/lib/firmware/qca/ornnv11.bin`
5. Reboot the device.

After the device boots, QCC2072 Bluetooth comes up and operates as expected.

## Known issues

<a id="known-issues" />

*No entries yet.*