Re: [edk2-devel] [PATCH v1 1/1] MdeModulePkg:Add Warm Reset for Xhc

["Pedro Falcato" <pedro.falcato@gmail.com>]

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On Thu, Nov 3, 2022 at 3:53 PM zhoucheng <zhoucheng@phytium.com.cn> wrote:

> Description according to Chapter 7.5.2 of USB 3.2 spec protocol.
> When the Usb state machine is in Inactive, the software is required
> to perform a warm reset operation.
>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Signed-off-by: Cheng Zhou <zhoucheng@phytium.com.cn>
> ---
>  MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
> b/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
> index c05431ff30ec..938c8e2e28f7 100644
> --- a/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
> +++ b/MdeModulePkg/Bus/Pci/XhciDxe/Xhci.c
> @@ -558,6 +558,20 @@ XhcSetRootHubPortFeature (
>        State |= XHC_PORTSC_RESET;
>        XhcWriteOpReg (Xhc, Offset, State);
>        XhcWaitOpRegBit (Xhc, Offset, XHC_PORTSC_PRC, TRUE,
> XHC_GENERIC_TIMEOUT);
> +
> +      //
> +      // Usb 3.2 spec 7.5.2
> +      // When the USB state machine is Inactive state, the device is
> abnormal.
> +      // eSS.Inactive is a state where a link has failed Enhanced
> SuperSpeed operation.Software
> +      // is required for warm reset intervention.This flag only applies
> to USB3 protocol ports.
> +      //
> +      State = XhcReadOpReg (Xhc, Offset);
> +      if ((((State & 0x1e0) >> 5) == 6) && ((State & 3) == 0)) {
> +        State |= 0x80000000;
>
Please use defines for all of these magic values, it improves readability
so much.

> +        XhcWriteOpReg (Xhc, Offset, State);
> +        XhcWaitOpRegBit (Xhc, Offset, XHC_PORTSC_PRC, TRUE,
> XHC_GENERIC_TIMEOUT);
> +        DEBUG ((DEBUG_INFO, "Warm Reset Successful! \n"));
> +      }
>        break;
>
>      case EfiUsbPortPower:
> --
> 2.17.1
>
>
>
> 
>
>
>

-- 
Pedro Falcato

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