From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754535AbcIITkP (ORCPT ); Fri, 9 Sep 2016 15:40:15 -0400 Received: from mail-lf0-f50.google.com ([209.85.215.50]:35990 "EHLO mail-lf0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753269AbcIITkM (ORCPT ); Fri, 9 Sep 2016 15:40:12 -0400 Subject: Re: [RESEND PATCH v7 3/4] usb: dwc2: assert phy reset when waking up in rk3288 platform To: Randy Li , linux-usb@vger.kernel.org References: <1473447580-10369-1-git-send-email-ayaka@soulik.info> <1473447580-10369-4-git-send-email-ayaka@soulik.info> 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, linux-rockchip@lists.infradead.org, robh+dt@kernel.org, randy.li@rock-chips.com From: Sergei Shtylyov Organization: Cogent Embedded Message-ID: <278fe308-fd6a-357a-5fc8-ae67ef11faf2@cogentembedded.com> Date: Fri, 9 Sep 2016 22:40:08 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <1473447580-10369-4-git-send-email-ayaka@soulik.info> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. On 09/09/2016 09:59 PM, 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_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 [...] > @@ -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 Caused. [...] MBR, Sergei