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References: <20211209072218.21651-1-chunfeng.yun@mediatek.com> <c448da77-f2f3-8b79-fc4b-b9dcff727c6e@linux.intel.com>
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From:   Jun Li <lijun.kernel@gmail.com>
Date:   Tue, 14 Dec 2021 16:00:35 +0800
Message-ID: <CAKgpwJXxtLwOjxjg3vFHiqS92j6rx_b1+C-bRwDnp+PBvXCMTg@mail.gmail.com>
Subject: Re: [PATCH] usb: xhci: skip re-check pending port event if hibernated
To:     Mathias Nyman <mathias.nyman@linux.intel.com>
Cc:     Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Linux USB List <linux-usb@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        linux-mediatek@lists.infradead.org,
        lkml <linux-kernel@vger.kernel.org>,
        Eddie Hung <eddie.hung@mediatek.com>,
        Yun-Chien Yu <yun-chien.yu@mediatek.com>
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Mathias Nyman <mathias.nyman@linux.intel.com> =E4=BA=8E2021=E5=B9=B412=E6=
=9C=8811=E6=97=A5=E5=91=A8=E5=85=AD 01:56=E5=86=99=E9=81=93=EF=BC=9A
>
> On 9.12.2021 9.22, Chunfeng Yun wrote:
> > When xHCI controller hibernated, the root hub lost power, if controller
> > support Port Power Control (PPC), PP is not set at xhci_resume() and
> > set by hub_reset_resume() later, so no need check pending port event.
> > If PPC is not supported, device is disconneced, seems do not send out
> > U3 LFPS wake signal, no need re-check again and drop 120ms delay to
> > save resume time.
> >
> > Reported-by: Yun-Chien Yu <yun-chien.yu@mediatek.com>
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
>
> Thanks, adding

Hi Mathias, Chunfeng

I have a question on this, if there is no any usb devices connected
before suspend, do we need this 120ms delay to check again?
So do we need one more condition to limit this like?
if (!pending_portevent && !hibernated && xhci_has_child_device())

thanks
Li Jun
>
> -Mathias