Re: [PATCH v3 0/3] usb: dwc3: parkmode_disable_ss_quirk on DWC3 controller

From: Neil Armstrong
Date: Fri Feb 21 2020 - 04:11:40 EST


On 19/02/2020 15:18, Neil Armstrong wrote:
> 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 v2 at [2]:
> - rebased on v5.6-rc2
>
> 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
> [1] https://lore.kernel.org/linux-amlogic/20200109101535.26812-1-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(+)
>

Please ignore this serie, the patch 3 subject is wrong.

Neil