USB error on LS1046 platform

USB error on LS1046 platform

[Alexander Wilhelm]

Hello developers,

I’m using an NXP LS1046A SoC with the integrated DWC3 USB controller in
host mode. On Linux v5.5.167 my USB flash drive was detected and mountable.
After upgrading to Linux v6.6.110 the USB flash drive is no longer
recognized. If it is already plugged in during boot phase I get the
following errors:

    xhci-hcd xhci-hcd.2.auto: Error while assigning device slot ID: Command Aborted
    xhci-hcd xhci-hcd.2.auto: Max number of devices this xHCI host supports is 127

I have narrowed the issue down to the following commit:

    136975c33894e7b48a6007af0f4c25f423bbd1de
    arm64: dts: ls1046a: make dma-coherent global to the SoC

When I revert this commit, USB works perfectly on my system.

I have already asked on the `linux-usb` mailing list
(https://lore.kernel.org/linux-usb/aTFr17xKxnWGG3vU@FUE-ALEWI-WINX/) and also
forwarded the message to `linux-arm-kernel`, but I haven’t received any replies
so far. Has anyone encountered this problem on the LS1046 or a similar platform?
Any hints or experiences would be greatly appreciated.


Best regards
Alexander Wilhelm

Re: USB error on LS1046 platform

[Rob Herring]

+Laurentiu, Li

On Tue, Jan 27, 2026 at 09:21:38AM +0100, Alexander Wilhelm wrote:
> Hello developers,
> 
> I’m using an NXP LS1046A SoC with the integrated DWC3 USB controller in
> host mode. On Linux v5.5.167 my USB flash drive was detected and mountable.
> After upgrading to Linux v6.6.110 the USB flash drive is no longer
> recognized. If it is already plugged in during boot phase I get the
> following errors:
> 
>     xhci-hcd xhci-hcd.2.auto: Error while assigning device slot ID: Command Aborted
>     xhci-hcd xhci-hcd.2.auto: Max number of devices this xHCI host supports is 127
> 
> I have narrowed the issue down to the following commit:
> 
>     136975c33894e7b48a6007af0f4c25f423bbd1de
>     arm64: dts: ls1046a: make dma-coherent global to the SoC

It's best to send this to the author(s) of the commit.

Looks like it needs to be reverted or USB marked non-coherent. That's 
Shawn's responsibility to apply and the author to send a fix (unless 
you want to). The DT maintainers don't take .dts patches.

> 
> When I revert this commit, USB works perfectly on my system.
> 
> I have already asked on the `linux-usb` mailing list
> (https://lore.kernel.org/linux-usb/aTFr17xKxnWGG3vU@FUE-ALEWI-WINX/) and also
> forwarded the message to `linux-arm-kernel`, but I haven’t received any replies
> so far. Has anyone encountered this problem on the LS1046 or a similar platform?
> Any hints or experiences would be greatly appreciated.
> 
> 
> Best regards
> Alexander Wilhelm