From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755254AbcHXI67 (ORCPT ); Wed, 24 Aug 2016 04:58:59 -0400 Received: from regular1.263xmail.com ([211.150.99.131]:51849 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753548AbcHXI5n (ORCPT ); Wed, 24 Aug 2016 04:57:43 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: randy.li@rock-chips.com X-FST-TO: kishon@ti.com X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: randy.li@rock-chips.com X-UNIQUE-TAG: <3e6de7c8b4416d2e1f65cf08c4c4948c> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [RESEND PATCH 3/4] usb: dwc2: assert phy reset when waking up in rk3288 platform To: John Youn , Randy Li , "linux-usb@vger.kernel.org" References: <4c931176-a09a-546c-d2b6-ea74028c78a2@cogentembedded.com> <1471807905-11323-1-git-send-email-ayaka@soulik.info> <49d2baf7-5f81-fc20-a805-f7a378d67a5e@synopsys.com> Cc: "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" , "eddie.cai@rock-chips.com" , "kishon@ti.com" From: Randy Li Organization: Fuzhou Rockchip Message-ID: <76f0ffdb-a3c6-f1e6-8177-b254ff5badaa@rock-chips.com> Date: Wed, 24 Aug 2016 16:54:16 +0800 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: <49d2baf7-5f81-fc20-a805-f7a378d67a5e@synopsys.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/24/2016 04:46 AM, John Youn wrote: > On 8/21/2016 12:32 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..f57c48a 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 > > Remove the trailing whitespaces in this comment. > > Run scripts/checkpatch.pl to catch these. I see. > >> + */ >> + if (of_device_is_compatible(np, "rockchip,rk3288-usb")) >> + hsotg->phy->ops->reset(hsotg->phy); >> + > > You should probably check for NULL before calling the reset() > callback. Sure. > > Also, I'd rather see a generic quirk property that you set for your > platform. > > Something like "phy_reset_on_wakeup_quirk". But Rob Herring want me to implied by the SoC specific compatible string. I agree with him. It is certainly bug in RK3288 platform. It is no found no the other platform. > > Also, try to preserve the version tag in your subject for all the > patches so that we can easily identify the latest version of the > series, like: > > [PATCH v5 3/4] ... > > And, typically "RESEND" means there are no code change. I see, I just make up my mind whether code style is new version before. I won't again. Thank you very much. > > Regards, > John > > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip > -- Randy Li The third produce department