Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753873AbcJSW6e (ORCPT ); Wed, 19 Oct 2016 18:58:34 -0400 Received: from smtprelay.synopsys.com ([198.182.47.9]:48219 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751288AbcJSW6b (ORCPT ); Wed, 19 Oct 2016 18:58:31 -0400 Subject: Re: [PATCH v8 2/3] usb: dwc2: assert phy reset when waking up in rk3288 platform To: =?UTF-8?B?6ZmI6LGq?= , Randy Li References: <1474743019-1050-1-git-send-email-ayaka@soulik.info> <1474743019-1050-3-git-send-email-ayaka@soulik.info> 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" From: John Youn Message-ID: Date: Wed, 19 Oct 2016 15:58:27 -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: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.9.139.0] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2936 Lines: 75 On 10/15/2016 8:07 AM, 陈豪 wrote: > 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？ > Yes, that's right, I missed that. It will have to be fixed. Regards, John