Re: [PATCH v2 1/1] usb: xhci: do not create and register shared_hcd when USB3.0 is disabled

[Thang Q. Nguyen]

On Mon, Jan 29, 2018 at 5:24 PM, Thang Q. Nguyen <tqnguyen@xxxxxxx> wrote:
> From: Tung Nguyen <tunguyen@xxxxxxx>
>
> Currently, hcd->shared_hcd always creates and registers to the usb-core.
> If, for some reasons, USB3 downstream port is disabled, no roothub port for
> USB3.0 is found. This causes kernel to display an error:
> hub 2-0:1.0: config failed, hub doesn't have any ports! (err -19)
> This patch checks and registers shared_hcd if USB3.0 downstream
> port is available.
>
> Signed-off-by: Tung Nguyen <tunguyen@xxxxxxx>
> ---
>  drivers/usb/host/xhci-plat.c |  9 ++++++---
>  drivers/usb/host/xhci.c      | 13 +++++++++++++
>  2 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 6f03830..bdb3975 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -293,9 +293,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
>         if (HCC_MAX_PSA(xhci->hcc_params) >= 4)
>                 xhci->shared_hcd->can_do_streams = 1;
>
> -       ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
> -       if (ret)
> -               goto dealloc_usb2_hcd;
> +       /* Just add the shared_hcd when USB3.0 downstream port is available */
> +       if (xhci->num_usb3_ports > 0) {
> +               ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
> +               if (ret)
> +                       goto dealloc_usb2_hcd;
> +       }
>
>         device_enable_async_suspend(&pdev->dev);
>         pm_runtime_put_noidle(&pdev->dev);
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 1eeb339..9d3b1ab 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -611,6 +611,19 @@ int xhci_run(struct usb_hcd *hcd)
>                 if (ret)
>                         xhci_free_command(xhci, command);
>         }
> +       /*
> +        * In case that the USB3.0 downstream port is not available
> +        * No one triggers to start the xHC which should be done
> +        * before finishing xhci_run
> +        */
> +       if (xhci->num_usb3_ports == 0) {
> +               if (xhci_start(xhci)) {
> +                       xhci_halt(xhci);
> +                       return -ENODEV;
> +               }
> +               xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
> +       }
> +
>         xhci_dbg_trace(xhci, trace_xhci_dbg_init,
>                         "Finished xhci_run for USB2 roothub");
>
> --
> 1.8.3.1
>
Hi,
Do you have any comment on the patch?