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

[Nicolas Boichat]

On Wed, Mar 28, 2018 at 5:53 PM Thang Q. Nguyen <tqnguyen@xxxxxxx> wrote:
>
> On Mon, Mar 5, 2018 at 5:22 PM, Thang Q. Nguyen <tqnguyen@xxxxxxx> wrote:
> > 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.

I'm working on a board with similar warning on boot (XHCI controller
without 3.0 support), and there is no more error on boot with your
patch.

However, I still see the USB 3.0 root hub, so I'm wondering if that's
expected or if we should find a way to remove it?
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

Apart from that:

Tested-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>

> >> 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?
> Hi,
> Do you have any comment on the patch?