Re: [PATCH v3] arm64: dts: ls208xa: use a pseudo-bus to constrain usb dma size

[Shawn Guo]

On Mon, Sep 25, 2023 at 06:10:15PM +0300, Laurentiu Tudor wrote:
> Wrap the usb controllers in an intermediate simple-bus and use it to
> constrain the dma address size of these usb controllers to the 40b
> that they generate toward the interconnect. This is required because
> the SoC uses 48b address sizes and this mismatch would lead to smmu
> context faults [1] because the usb generates 40b addresses while the
> smmu page tables are populated with 48b wide addresses.
> 
> [1]
> xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
> xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1
> xhci-hcd xhci-hcd.0.auto: hcc params 0x0220f66d hci version 0x100 quirks 0x0000000002000010
> xhci-hcd xhci-hcd.0.auto: irq 108, io mem 0x03100000
> xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
> xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 2
> xhci-hcd xhci-hcd.0.auto: Host supports USB 3.0 SuperSpeed
> arm-smmu 5000000.iommu: Unhandled context fault: fsr=0x402, iova=0xffffffb000, fsynr=0x0, cbfrsynra=0xc01, cb=3
> 
> Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

Applied, thanks!