Re: [PATCH v9 1/2] usb: dwc2: assert phy reset when waking up in rk3288 platform

[ayaka]

On 10/22/2016 03:27 AM, John Youn wrote:
> On 10/20/2016 11:38 AM, Randy Li wrote:
> > On the rk3288 USB host-only port (the one that's not the OTG-enabled
> > port) the PHY can get into a bad state when a wakeup is asserted (not
> > just a wakeup from full system suspend but also a wakeup from
> > autosuspend).
> >
> > We can get the PHY out of its bad state by asserting its "port reset",
> > but unfortunately that seems to assert a reset onto the USB bus so it
> > could confuse things if we don't actually deenumerate / reenumerate the
> > device.
> >
> > We can also get the PHY out of its bad state by fully resetting it using
> > the reset from the CRU (clock reset unit) in chip, which does a more full
> > reset.  The CRU-based reset appears to actually cause devices on the bus
> > to be removed and reinserted, which fixes the problem (albeit in a hacky
> > way).
> >
> > It's unfortunate that we need to do a full re-enumeration of devices at
> > wakeup time, but this is better than alternative of letting the bus get
> > wedged.
> >
> > Signed-off-by: Randy Li <ayaka@xxxxxxxxxxx>
> > ---
> >   drivers/usb/dwc2/core.h      |  1 +
> >   drivers/usb/dwc2/core_intr.c | 11 +++++++++++
> >   drivers/usb/dwc2/platform.c  |  9 +++++++++
> >   3 files changed, 21 insertions(+)
> >
> > diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> > index 2a21a04..e91ddbc 100644
> > --- a/drivers/usb/dwc2/core.h
> > +++ b/drivers/usb/dwc2/core.h
> > @@ -859,6 +859,7 @@ struct dwc2_hsotg {
> >   	unsigned int ll_hw_enabled:1;
> >   
> >   	struct phy *phy;
> > +	struct work_struct phy_rst_work;
> >   	struct usb_phy *uphy;
> >   	struct dwc2_hsotg_plat *plat;
> >   	struct regulator_bulk_data supplies[ARRAY_SIZE(dwc2_hsotg_supply_names)];
> > diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
> > index d85c5c9..c3d2168 100644
> > --- a/drivers/usb/dwc2/core_intr.c
> > +++ b/drivers/usb/dwc2/core_intr.c
> > @@ -345,6 +345,7 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
> >   static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
> >   {
> >   	int ret;
> > +	struct device_node *np = hsotg->dev->of_node;
> >   
> >   	/* Clear interrupt */
> >   	dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
> > @@ -379,6 +380,16 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
> >   			/* Restart the Phy Clock */
> >   			pcgcctl &= ~PCGCTL_STOPPCLK;
> >   			dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
> > +
> > +			/*
> > +			 * It is a quirk in Rockchip RK3288, causing by
> > +			 * a hardware bug. This will propagate out and
> > +			 * eventually we'll re-enumerate the device.
> > +			 * Not great but the best we can do
> > +			 */
> > +			if (of_device_is_compatible(np, "rockchip,rk3288-usb"))
> > +				schedule_work(&hsotg->phy_rst_work);
> > +
> >   			mod_timer(&hsotg->wkp_timer,
> >   				  jiffies + msecs_to_jiffies(71));
> >   		} else {
> > diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> > index 8e1728b..65953cf 100644
> > --- a/drivers/usb/dwc2/platform.c
> > +++ b/drivers/usb/dwc2/platform.c
> > @@ -366,6 +366,14 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
> >   	return ret;
> >   }
> >   
> > +/* Only used to reset usb phy at interrupter runtime */
> > +static void dwc2_reset_phy_work(struct work_struct *data)
> > +{
> > +	struct dwc2_hsotg *hsotg = container_of(data, struct dwc2_hsotg,
> > +			phy_rst_work);
> > +	phy_reset(hsotg->phy);
> > +}
> > +
> >   static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
> >   {
> >   	int i, ret;
> > @@ -410,6 +418,7 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
> >   			return ret;
> >   		}
> >   	}
> > +	INIT_WORK(&hsotg->phy_rst_work, dwc2_reset_phy_work);
> >   
> >   	if (!hsotg->phy) {
> >   		hsotg->uphy = devm_usb_get_phy(hsotg->dev, USB_PHY_TYPE_USB2);
> Hi Randy,
>
> This fails compile if CONFIG_GENERIC_PHY is disabled. I think you need
> to make a fix to your phy_reset patch first.
In the last time, cac18ecb6f44b11bc303d7afbae3887b27938fa4 have not been 
merged, I though the
[PATCH v8 1/3] phy: Add reset callback for not generic phy have been 
merged before that. when the rebase abandon it.
Should re-send that patch? As the mainline have not been affected, could 
you arrange a squash for it?
> Regards,
> John