Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935947AbcJUT15 (ORCPT ); Fri, 21 Oct 2016 15:27:57 -0400 Received: from smtprelay2.synopsys.com ([198.182.60.111]:41307 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754893AbcJUT1z (ORCPT ); Fri, 21 Oct 2016 15:27:55 -0400 Subject: Re: [PATCH v9 1/2] usb: dwc2: assert phy reset when waking up in rk3288 platform To: Randy Li , "linux-usb@vger.kernel.org" References: <1476988627-14953-1-git-send-email-ayaka@soulik.info> <1476988627-14953-2-git-send-email-ayaka@soulik.info> From: John Youn CC: "John.Youn@synopsys.com" , "kishon@ti.com" , "felipe.balbi@linux.intel.com" , "mark.rutland@arm.com" , "devicetree@vger.kernel.org" , "heiko@sntech.de" , "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "robh+dt@kernel.org" , "randy.li@rock-chips.com" Message-ID: <4ee5817d-0076-9974-8b0e-182a0241e1f5@synopsys.com> Date: Fri, 21 Oct 2016 12:27:32 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1476988627-14953-2-git-send-email-ayaka@soulik.info> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.9.138.204] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3798 Lines: 105 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 > --- > 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. Regards, John