Re: [PATCH v1] arm64: dts: ti: k3-am62-main: disable usb lpm

[Francesco Dolcini]

On Fri, Feb 09, 2024 at 02:02:12PM +0100, Andrejs Cainikovs wrote:
> From: Andrejs Cainikovs <andrejs.cainikovs@xxxxxxxxxxx>
> 
> AM62 USB works with some devices, while failing to operate with others.
> 
> [  560.189822] xhci-hcd xhci-hcd.4.auto: xHCI Host Controller
> [  560.195631] xhci-hcd xhci-hcd.4.auto: new USB bus registered, assigned bus number 2
> [  574.388509] xhci-hcd xhci-hcd.4.auto: can't setup: -110
> [  574.393814] xhci-hcd xhci-hcd.4.auto: USB bus 2 deregistered
> [  574.399544] xhci-hcd: probe of xhci-hcd.4.auto failed with error -110
> 
> This seems to be related to LPM (Link Power Management), and disabling it
> turns USB into reliable working state.
> 
> As per AM62 reference manual:
> 
> > 4.8.2.1 USB2SS Unsupported Features
> >
> > The following features are not supported on this family of devices:
> > ...
> > - USB 2.0 ECN: Link Power Management (LPM)
> > ...
> 
> Fixes: 2240f96cf3cd ("arm64: dts: ti: k3-am62-main: Add support for USB")
> Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@xxxxxxxxxxx>

Reviewed-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>

Francesco