The Radxa Dragon Q6A is a compact single-board computer based on the
Qualcomm QCS6490 SoC (sc7280 family). A basic DTS for this board
already exists in mainline. This series enables the remaining hardware
and fixes platform-specific issues required for correct operation when
booting via UEFI firmware.

Patches 1-3 fix platform issues affecting QCS6490 boards booting via
UEFI firmware:

- The RSC hardware solver is left active by the UEFI firmware, causing
  a security violation if the kernel attempts to reinitialize it.
- EFI variable access requires the board compatible string in the SCM
  allowlist.
- The RA620 DP-to-HDMI bridge does not complete link training at
  voltage swing level 3. Capping at level 2 matches the vendor kernel
  behaviour and allows HDMI output to work correctly.

Patches 4-6 add DTS nodes enabling:

- GPU (Adreno 643) with clock controller and GMU
- DisplayPort output via RA620 passive DP-to-HDMI bridge
- USB3 SuperSpeed via the QMP combo PHY shared with DisplayPort

The following has been confirmed working on this board with mainline
drivers:
- KDE Plasma 6.6.5 desktop on Wayland with GPU acceleration
- HDMI display output via RA620 passive DP-to-HDMI bridge
- USB3 SuperSpeed (5Gbps confirmed via lsusb)
- OpenGL 4.6 and Vulkan 1.3 via Mesa Freedreno/Turnip
- Hardware video decode/encode via Venus (H.264, HEVC, VP9, MPEG-2)
- Audio via WCD938x codec (headphone output, microphone, HDMI audio)
- FastRPC interface to Hexagon DSP available (/dev/fastrpc-cdsp)
  though inference workloads have not been tested

With the out-of-tree AIC8800 driver for the onboard Quectel FCU760K
WiFi/BT module, all remaining hardware on the board is functional
under mainline Linux.

Tested on Radxa Dragon Q6A (QCS6490) with mainline Linux 7.0.9.



Graham O'Connor (6):
  soc: qcom: rpmh-rsc: Skip TCS init when RSC is managed by firmware
  firmware: qcom: scm: Allow EFI variable access on Radxa Dragon Q6A
  drm/msm/dp: Limit voltage swing level to 2 for RA620 bridge
  arm64: dts: qcom: qcs6490-radxa-dragon-q6a: Add regulator supplies and
    disable EUD
  arm64: dts: qcom: qcs6490-radxa-dragon-q6a: Enable GPU and display
    pipeline
  arm64: dts: qcom: qcs6490-radxa-dragon-q6a: Enable USB3 SuperSpeed

 .../dts/qcom/qcs6490-radxa-dragon-q6a.dts     | 176 ++++++++++++++++++
 drivers/firmware/qcom/qcom_scm.c              |   1 +
 drivers/gpu/drm/msm/dp/dp_link.h              |   2 +-
 drivers/soc/qcom/rpmh-rsc.c                   |  14 ++
 4 files changed, 192 insertions(+), 1 deletion(-)

-- 
2.53.0

Thank you to Konrad, Neil, and others for the very prompt and helpful reviews.

Based on the feedback received, I think it best to withdraw this series to
address the issues raised, most notobly:

1. The DP_TRAIN_LEVEL_MAX change (patch 3) is too broad - it affects all
   devices using the Qualcomm MSM DP driver rather than being specific to
   the RA620 bridge. A proper fix should be implemented at the bridge
   level. This is going to take more investigation.

2. The display DT nodes (patch 5) should use the radxa,ra620 compatible
   string per the existing Radxa upstream series from Xilin Wu, and the
   lane ordering needs correcting.

3. The rpmh-rsc early return (patch 1) needs further review regarding
   the implications of returning before full driver initialization.

4. DTS patch label dependency issue (sorry) 

I'll integrate with the Radxa upstream effort, re-evaluate the other areas
and resubmit corrected patches addressing these concerns at a later date.

Thanks for the feedback.

Cheers

Graham

On 5/22/2026 6:13 PM, Graham O'Connor wrote:
> Thank you to Konrad, Neil, and others for the very prompt and helpful reviews.
> 
> Based on the feedback received, I think it best to withdraw this series to
> address the issues raised, most notobly:
> 
> 1. The DP_TRAIN_LEVEL_MAX change (patch 3) is too broad - it affects all
>     devices using the Qualcomm MSM DP driver rather than being specific to
>     the RA620 bridge. A proper fix should be implemented at the bridge
>     level. This is going to take more investigation.
> 
> 2. The display DT nodes (patch 5) should use the radxa,ra620 compatible
>     string per the existing Radxa upstream series from Xilin Wu, and the
>     lane ordering needs correcting.
> 
> 3. The rpmh-rsc early return (patch 1) needs further review regarding
>     the implications of returning before full driver initialization.
> 
> 4. DTS patch label dependency issue (sorry)
> 
> I'll integrate with the Radxa upstream effort, re-evaluate the other areas
> and resubmit corrected patches addressing these concerns at a later date.
> 
> Thanks for the feedback.
> 
> Cheers
> 
> Graham

Hi Graham,

Thanks for working on the additional hardware bring-up for Q6A upstream 
support. I'm really glad to see someone pushing this forward.

I actually posted a patch series [1] last month, and it is generally in 
good shape. Unfortunately, I got busy with other work and haven't had a 
chance to send v2 yet.

If it helps, please feel free to take over that series and fold your 
additional patches into it. I think that would be a good way to move 
things forward.

Also, I believe patches 10-12 in my series are no longer needed and can 
be dropped.

Thank you again for the work you have done.

[1] 
https://patchwork.kernel.org/project/linux-arm-msm/list/?series=1078242&state=%2A&archive=both

-- 
Best regards,
Xilin Wu <sophon@radxa.com>