In certain circumstances, the XHCI SuperSpeed instance in park mode can fail to recover, thus on Amlogic G12A/G12B/SM1 SoCs when there is high load on the single XHCI SuperSpeed instance, the controller can crash like: xhci-hcd xhci-hcd.0.auto: xHCI host not responding to stop endpoint command. xhci-hcd xhci-hcd.0.auto: Host halt failed, -110 xhci-hcd xhci-hcd.0.auto: xHCI host controller not responding, assume dead xhci-hcd xhci-hcd.0.auto: xHCI host not responding to stop endpoint command. hub 2-1.1:1.0: hub_ext_port_status failed (err = -22) xhci-hcd xhci-hcd.0.auto: HC died; cleaning up usb 2-1.1-port1: cannot reset (err = -22) Setting the PARKMODE_DISABLE_SS bit in the DWC3_USB3_GUCTL1 mitigates the issue. The bit is described as : "When this bit is set to '1' all SS bus instances in park mode are disabled" The bug has been reproduced by Jun Li <lijun.kernel@xxxxxxxxx> and confirmed by Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> with the explanation: > The GUCTL1.PARKMODE_DISABLE_SS is only available in dwc_usb3 controller > running in host mode. This should not be set for other IPs. > This can be disabled by default based on IP, but I recommend to have a > property to enable this feature for devices that need this. Changes since v1 at [1]: - added rob review tag - added Thinh Nguyen in commit log [1] https://lore.kernel.org/linux-amlogic/20191014141718.22603-1-narmstrong@xxxxxxxxxxxx Neil Armstrong (3): doc: dt: bindings: usb: dwc3: Update entries for disabling SS instances in park mode usb: dwc3: gadget: Add support for disabling SS instances in park mode arm64: dts: g12-common: add parkmode_disable_ss_quirk on DWC3 controller Documentation/devicetree/bindings/usb/dwc3.txt | 2 ++ arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi | 1 + drivers/usb/dwc3/core.c | 5 +++++ drivers/usb/dwc3/core.h | 4 ++++ 4 files changed, 12 insertions(+) -- 2.22.0
