From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A3AEC43334 for ; Tue, 14 Jun 2022 19:37:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239205AbiFNThS (ORCPT ); Tue, 14 Jun 2022 15:37:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234362AbiFNThP (ORCPT ); Tue, 14 Jun 2022 15:37:15 -0400 Received: from alexa-out.qualcomm.com (alexa-out.qualcomm.com [129.46.98.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DABB01AD9C; Tue, 14 Jun 2022 12:37:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1655235435; x=1686771435; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=ry/MW3cGwWBXJo5LFJEWkEv0wSGZc+G+X/VY17t5peg=; b=PjVpzy4ii1sO+Qcgo7VS3vnSE6g0z3LunX42RtB6IZPu9VfOFBG1cI5m 41dp9diZ36CDK90t54GdF2tx7ubFxYD8gs7eYUekcU9meZYvMYQws7d25 mGuwDnIzGOBOdscPmIAxROxyoaVcXi9Ntm11OroU+vFVBotcmnc8iuYlv E=; Received: from ironmsg-lv-alpha.qualcomm.com ([10.47.202.13]) by alexa-out.qualcomm.com with ESMTP; 14 Jun 2022 12:37:14 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg-lv-alpha.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2022 12:37:13 -0700 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Tue, 14 Jun 2022 12:37:13 -0700 Received: from [10.216.52.176] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Tue, 14 Jun 2022 12:37:07 -0700 Message-ID: <4b22f283-0897-6729-e54f-a8bb47b5c368@quicinc.com> Date: Wed, 15 Jun 2022 01:07:01 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v20 2/5] usb: dwc3: core: Host wake up support from system suspend Content-Language: en-US To: Matthias Kaehlcke CC: Krzysztof Kozlowski , Rob Herring , Andy Gross , Bjorn Andersson , Greg Kroah-Hartman , Felipe Balbi , Stephen Boyd , Doug Anderson , Mathias Nyman , , , , , , , , References: <1654158277-12921-1-git-send-email-quic_kriskura@quicinc.com> <1654158277-12921-3-git-send-email-quic_kriskura@quicinc.com> From: Krishna Kurapati PSSNV In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 6/14/2022 11:23 PM, Matthias Kaehlcke wrote: > On Mon, Jun 13, 2022 at 11:08:32AM -0700, Matthias Kaehlcke wrote: >> On Mon, Jun 06, 2022 at 01:45:51PM -0700, Matthias Kaehlcke wrote: >>> On Thu, Jun 02, 2022 at 12:35:42PM -0700, Matthias Kaehlcke wrote: >>>> Hi Krishna, >>>> >>>> with this version I see xHCI errors on my SC7180 based system, like >>>> these: >>>> >>>> [ 65.352605] xhci-hcd xhci-hcd.13.auto: xHC error in resume, USBSTS 0x401, Reinit >>>> >>>> [ 101.307155] xhci-hcd xhci-hcd.13.auto: WARN: xHC CMD_RUN timeout >>>> >>>> After resume a downstream hub isn't enumerated again. >>>> >>>> So far I didn't see those with v13, but I aso saw the first error with >>>> v16. >>> It also happens with v13, but only when a wakeup capable vUSB <= 2 >>> device is plugged in. Initially I used a wakeup capable USB3 to >>> Ethernet adapter to trigger the wakeup case, however older versions >>> of this series that use usb_wakeup_enabled_descendants() to check >>> for wakeup capable devices didn't actually check for vUSB > 2 >>> devices. >>> >>> So the case were the controller/PHYs is powered down works, but >>> the controller is unhappy when the runtime PM path is used during >>> system suspend. >> The issue isn't seen on all systems using dwc3-qcom and the problem starts >> during probe(). The expected probe sequence is something like this: >> >> dwc3_qcom_probe >> dwc3_qcom_of_register_core >> dwc3_probe >> >> if (device_can_wakeup(&qcom->dwc3->dev)) >> ... >> >> The important part is that device_can_wakeup() is called after dwc3_probe() >> has completed. That's what I see on a QC SC7280 system, where wakeup is >> generally working with these patches. >> >> However on a QC SC7180 system dwc3_probe() is deferred and only executed after >> dwc3_qcom_probe(). As a result the device_can_wakeup() call returns false. >> With that the controller/driver ends up in an unhappy state after system >> suspend. >> >> Probing is deferred on SC7180 because device_links_check_suppliers() finds >> that '88e3000.phy' isn't ready yet. > It seems device links could be used to make sure the dwc3 core is present: > > Another example for an inconsistent state would be a device link that > represents a driver presence dependency, yet is added from the consumer’s > ->probe callback while the supplier hasn’t probed yet: Had the driver core > known about the device link earlier, it wouldn’t have probed the consumer > in the first place. The onus is thus on the consumer to check presence of > the supplier after adding the link, and defer probing on non-presence. > > https://www.kernel.org/doc/html/v5.18/driver-api/device_link.html#usage > > > You could add something like this to dwc3_qcom_of_register_core(): > > > device_link_add(dev, &qcom->dwc3->dev, > DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_AUTOPROBE_CONSUMER); > > if (qcom->dwc3->dev.links.status != DL_DEV_DRIVER_BOUND) > ret = -EPROBE_DEFER; > > > From the doc it isn't clear how the consumer is supposed to check presence > of the supplier, the above check of the link status is also used in > drivers/cpufreq/mediatek-cpufreq.c , but not elsewhere outside of the > driver framework. Hi Mathias,     Thanks for the input. I will try the above snippet and confirm if probe call happens in sync with of_platform_populate in dwc3_qcom_of_register_core Regards, Krishna,