Re: [PATCH] usb: dwc2: resume root hub when device detect with suspend state

[Julius Werner]

On Mon, Nov 17, 2014 at 5:14 AM, Kever Yang <kever.yang@xxxxxxxxxxxxxx> wrote:
> After we implement the bus_suspend/resume, auto suspend id enabled.
> The root hub will be auto suspend if there is no device connected,
> we need to resume the root hub when a device connect detect.
>
> This patch tested on rk3288.
>
> Signed-off-by: Roy Li <roy.li@xxxxxxxxxxxxxx>
> Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>
> ---
>
>  drivers/usb/dwc2/hcd_intr.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c
> index 551ba87..c8299fd 100644
> --- a/drivers/usb/dwc2/hcd_intr.c
> +++ b/drivers/usb/dwc2/hcd_intr.c
> @@ -355,6 +355,13 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg)
>                 hprt0_modify |= HPRT0_CONNDET;
>
>                 /*
> +                * Check if root hub is in suspend state
> +                * if root hub in suspend, resume it.
> +                */
> +               if ((bus->root_hub) && (hcd->state == HC_STATE_SUSPENDED))

What is bus->root_hub checking for? Is there any chance that this
could be NULL here?

> +                       usb_hcd_resume_root_hub(hcd);
> +
> +               /*
>                  * The Hub driver asserts a reset when it sees port connect
>                  * status change flag
>                  */
> --
> 1.9.1

Seems sensible in general. Does this actually fix the problem Doug was
reporting?
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