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

[Kever Yang]

Hi Julius,

On 11/18/2014 05:21 AM, Julius Werner wrote:
> 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?
I add bus->root_hub check because the _dwc2_hcd_start check this before it
call the usb_hcd_resume_root_hub.
I think we don't need this check for the root_hub must be there if we 
register
the HCD success, right?
I will remove this in next version.
> > +                       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?
Yes, this fix the problem Doug reported with my dwc2 hcd suspend/resume 
patch.

- Kever

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