Re: [PATCH v10 2/6] usb: dwc3: core: Host wake up support from system suspend

[Jun Li <lijun.kernel@gmail.com>]

Sandeep Maheswaram <quic_c_sanm@quicinc.com> 于2022年1月17日周一 22:03写道：
>
> 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 = dwc3_core_init_for_resume(dwc);
>                         if (ret)
>                                 return ret;
> --
> 2.7.4
>