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From:   Jun Li <lijun.kernel@gmail.com>
Date:   Tue, 18 Jan 2022 16:57:50 +0800
Message-ID: <CAKgpwJUpMZTUKRbuWye8Qxjw6odqTS=ZLFLnPfunc=iA79ckew@mail.gmail.com>
Subject: Re: [PATCH v10 2/6] usb: dwc3: core: Host wake up support from system suspend
To:     Sandeep Maheswaram <quic_c_sanm@quicinc.com>,
        Li Jun <jun.li@nxp.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Felipe Balbi <balbi@kernel.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Doug Anderson <dianders@chromium.org>,
        Matthias Kaehlcke <mka@chromium.org>,
        Mathias Nyman <mathias.nyman@intel.com>,
        linux-arm-msm@vger.kernel.org,
        Linux USB List <linux-usb@vger.kernel.org>,
        lkml <linux-kernel@vger.kernel.org>, quic_pkondeti@quicinc.com,
        quic_ppratap@quicinc.com
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Sandeep Maheswaram <quic_c_sanm@quicinc.com> =E4=BA=8E2022=E5=B9=B41=E6=9C=
=8817=E6=97=A5=E5=91=A8=E4=B8=80 22:03=E5=86=99=E9=81=93=EF=BC=9A
>
> Avoiding phy powerdown when wakeup capable devices are connected
> by checking wakeup property of xhci plat device.
> Phy should be on to wake up the device from suspend using wakeup capable
> devices such as keyboard and mouse.
>
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> Tested-by: Brian Norris <briannorris@chromium.org>
> ---
> Remove redundant else part in dwc3_resume_common. This will not be
> required if GDSC is always on during suspend/resume.
>
>
>  drivers/usb/dwc3/core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index f4c0995..e7a5e3f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1789,7 +1789,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm=
_message_t msg)
>                 dwc3_core_exit(dwc);
>                 break;
>         case DWC3_GCTL_PRTCAP_HOST:
> -               if (!PMSG_IS_AUTO(msg)) {
> +               if (!PMSG_IS_AUTO(msg) && !device_may_wakeup(&dwc->xhci->=
dev)) {
>                         dwc3_core_exit(dwc);
>                         break;
>                 }
> @@ -1850,7 +1850,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_=
message_t msg)
>                 spin_unlock_irqrestore(&dwc->lock, flags);
>                 break;
>         case DWC3_GCTL_PRTCAP_HOST:
> -               if (!PMSG_IS_AUTO(msg)) {
> +               if (!PMSG_IS_AUTO(msg) && !device_may_wakeup(&dwc->xhci->=
dev)) {

If XHCI_SKIP_PHY_INIT is not set, I see the usb core will help to
handle phy power on/off and init/exit via drivers/usb/core/phy.c, so
if the wakeup is enabled for controller, then finally the phy will not
be power off/exit. I am wondering if this change is actually required if
that is the case.

Sorry for the late comment.

Li Jun


>                         ret =3D dwc3_core_init_for_resume(dwc);
>                         if (ret)
>                                 return ret;
> --
> 2.7.4
>