Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754670AbcJOPHq (ORCPT ); Sat, 15 Oct 2016 11:07:46 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:34835 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751226AbcJOPHi (ORCPT ); Sat, 15 Oct 2016 11:07:38 -0400 MIME-Version: 1.0 In-Reply-To: <1474743019-1050-3-git-send-email-ayaka@soulik.info> References: <1474743019-1050-1-git-send-email-ayaka@soulik.info> <1474743019-1050-3-git-send-email-ayaka@soulik.info> From: =?UTF-8?B?6ZmI6LGq?= Date: Sat, 15 Oct 2016 23:07:36 +0800 Message-ID: Subject: Re: [PATCH v8 2/3] usb: dwc2: assert phy reset when waking up in rk3288 platform To: Randy Li Cc: linux-usb@vger.kernel.org, John.Youn@synopsys.com, kishon@ti.com, felipe.balbi@linux.intel.com, mark.rutland@arm.com, devicetree@vger.kernel.org, Heiko Stuebner , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, robh+dt@kernel.org, randy.li@rock-chips.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id u9FF8EQI028234 Content-Length: 2744 Lines: 66 2016-09-25 2:50 GMT+08:00 Randy Li : > 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_intr.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c > index d85c5c9..af27edc 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")) > + phy_reset(hsotg->phy); It will call mutex_lock in phy_reset. > + > mod_timer(&hsotg->wkp_timer, > jiffies + msecs_to_jiffies(71)); > } else { > -- > 2.7.4 > What is the status of this patch？ Sleeping calls(phy_reset ==> mutex) shouldn't be used in irq handler. Randy will correct that？