linux-kernel - Re: [PATCH] usb: chipidea: support generic phy in PM code path

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Message-ID: <20160822143921.36b6f95a@xhacker>
Date:   Mon, 22 Aug 2016 14:39:21 +0800
From:   Jisheng Zhang <jszhang@...vell.com>
To:     Peter Chen <hzpeterchen@...il.com>
CC:     <Peter.Chen@....com>, <gregkh@...uxfoundation.org>,
        <linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] usb: chipidea: support generic phy in PM code path

Hi Peter,

On Mon, 22 Aug 2016 13:33:08 +0800 Peter Chen wrote:

> On Fri, Aug 19, 2016 at 08:10:13PM +0800, Jisheng Zhang wrote:
> > Support generic phy in PM code path: call phy_power_off/phy_power_on
> > in ci_controller_suspend/ci_controller_resume.
> > 
> > Signed-off-by: Jisheng Zhang <jszhang@...vell.com>
> > ---
> >  drivers/usb/chipidea/core.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
> > index ae12595..ef9fb0b 100644
> > --- a/drivers/usb/chipidea/core.c
> > +++ b/drivers/usb/chipidea/core.c
> > @@ -1116,6 +1116,7 @@ static void ci_controller_suspend(struct ci_hdrc *ci)
> >  		usleep_range(ci->platdata->phy_clkgate_delay_us,
> >  			     ci->platdata->phy_clkgate_delay_us + 50);
> >  	usb_phy_set_suspend(ci->usb_phy, 1);
> > +	phy_power_off(ci->phy);  
> 
> How could you support USB wakeup after PHY is powered off?

Per my understanding, the PHY's power off just power off data communication part
but leaves the circuits involved in wakeup detection active.

Thanks,
Jisheng

> 
> Peter
> 
> >  	ci->in_lpm = true;
> >  	enable_irq(ci->irq);
> >  }
> > @@ -1132,9 +1133,10 @@ static int ci_controller_resume(struct device *dev)
> >  	}
> >  
> >  	ci_hdrc_enter_lpm(ci, false);
> > -	if (ci->usb_phy) {
> > +	if (ci->usb_phy || ci->phy) {
> >  		usb_phy_set_suspend(ci->usb_phy, 0);
> >  		usb_phy_set_wakeup(ci->usb_phy, false);
> > +		phy_power_on(ci->phy);
> >  		hw_wait_phy_stable();
> >  	}
> >  
> > -- 
> > 2.9.3
> > 
> > --
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>