Re: [PATCH] arm64: dts: qcom: glymur: Mark USB controllers dma-coherent

[Dmitry Baryshkov]

On Wed, Aug 12, 2026 at 05:40:14PM +0200, Greg Ociepka wrote:
> All five USB controller nodes on Glymur (usb_0, usb_1, usb_2, usb_hs,
> usb_mp) are missing the dma-coherent property, which Hamoa carries on
> all of its USB controllers. Krishna Kurapati confirmed the Glymur USB
> controllers are dma-coherent [1].
> 
> Without the property the kernel treats USB DMA buffers as non-coherent
> and performs cache maintenance on every transfer, which coherent
> hardware makes redundant.
> 
> Follow-up to the clock/power/bandwidth votes patch [2], kept separate
> so the already-reviewed patch stands as is.
> 
> Tested on an Asus Zenbook A16 (UX3607OA): all controllers enumerate
> their devices as before and a 64 MiB write plus two O_DIRECT
> read-backs over USB mass storage produce identical checksums.
> 
> [1] https://lore.kernel.org/linux-arm-msm/f92cc91e-6e5c-4375-aaa6-f079a165f4b5@xxxxxxxxxxxxxxxx/
> [2] https://lore.kernel.org/linux-arm-msm/20260812083522.774711-1-greg@xxxxxxxxxxxxx/
> 
> Fixes: 4eee57dd4df9 ("arm64: dts: qcom: glymur: Add USB related nodes")
> Signed-off-by: Greg Ociepka <greg@xxxxxxxxxxxxx>
> Assisted-by: Claude:fable-5
> ---
>  arch/arm64/boot/dts/qcom/glymur.dtsi | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>


-- 
With best wishes
Dmitry