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 DB4E4EB64D9 for ; Tue, 27 Jun 2023 18:09:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229623AbjF0SJg (ORCPT ); Tue, 27 Jun 2023 14:09:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjF0SJe (ORCPT ); Tue, 27 Jun 2023 14:09:34 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4C41187 for ; Tue, 27 Jun 2023 11:08:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1687889325; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XIzaMLEoZseg15rsHJ94wr9W2L80SXyc2pmPqG7NjnU=; b=KRxG/Vs9StJ623EP04GS/u5tkac1V3Mb02Iep7H2DhNnowgmFSIptOPF7Hz4pM+VhYYp7f 4vXcgn9QVYfVUpHx42sazp+o+IvUMMnZl2sGyFW0gsbcAjzuwX0h2OLzYXHqt4v8akro3G cleQ1aO6rkdQJtPGFsoV3o8sIpO0Muk= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-65-EFY3so1GNnCWbGsgdXu4UQ-1; Tue, 27 Jun 2023 14:08:44 -0400 X-MC-Unique: EFY3so1GNnCWbGsgdXu4UQ-1 Received: by mail-qk1-f199.google.com with SMTP id af79cd13be357-765a1a97103so306572485a.1 for ; Tue, 27 Jun 2023 11:08:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687889324; x=1690481324; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=XIzaMLEoZseg15rsHJ94wr9W2L80SXyc2pmPqG7NjnU=; b=KSaApNDE8EgGRshbeE8IQdZMdejkQEoHZV4UkfmhxJSPpydNKftEGIOVS8XQEfmYeX nSzXKuYD5/FeNJ+Jpjj1QCli2lBsSBOsMPBbWwbxNkhHLj7lqxGaF8Cmcrf0l3RpzNWC 9W1JmsnVCGEcSR8yi26pZVrj8+NfDot7eSyKo6x1M1Z9qWJVxPaPkEwCoq78AYB1AixU pQ49x8nsfrpggiSHkOxP3luxIDMdvz9Wkd5nvY35/XjTdN1M2QbHOkVy5Dy4TNB4YUp7 8Ac9Igq5/GhWGyHN+jFyQkZsD74fngUXrUVnxaBZN6V/O+s1XE1HC/TtDMTLeA3jbjRE OYyw== X-Gm-Message-State: AC+VfDyIUK6RRt3xnrOx4poytOvAOfHtmGEhb4ggybTNP6pYC3XqoLc6 474ofVn4CgitQvIq5Mr2q5+zgWyzE7wR1dxxwsZVh0BsmPMgm6BQgi4fVhzeFaM8Xv2U8WdL0VD 5Y9VczpyEFILy6ijfsO78TS5o7w== X-Received: by 2002:a05:620a:4087:b0:766:fbe6:ccbc with SMTP id f7-20020a05620a408700b00766fbe6ccbcmr5700133qko.29.1687889324173; Tue, 27 Jun 2023 11:08:44 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ7TDVN2FeMGh6qcSDmZy8YGLhDuYZ5iNM3siut168C5HboPBzGXzZVtnAVC+3BFKsCrtFSPcQ== X-Received: by 2002:a05:620a:4087:b0:766:fbe6:ccbc with SMTP id f7-20020a05620a408700b00766fbe6ccbcmr5700109qko.29.1687889323884; Tue, 27 Jun 2023 11:08:43 -0700 (PDT) Received: from fedora ([107.171.218.122]) by smtp.gmail.com with ESMTPSA id u12-20020ae9c00c000000b0076264532630sm4141287qkk.121.2023.06.27.11.08.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Jun 2023 11:08:43 -0700 (PDT) Date: Tue, 27 Jun 2023 14:08:41 -0400 From: Adrien Thierry To: Bjorn Andersson Cc: Andy Gross , Konrad Dybcio , Vinod Koul , Kishon Vijay Abraham I , linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org Subject: Re: [PATCH v3 2/3] phy: qcom-snps-femto-v2: add system sleep PM ops Message-ID: References: <20230622194021.80892-1-athierry@redhat.com> <20230622194021.80892-3-athierry@redhat.com> <52qapxj7sdearduro3iiqqpekrltc5zviwgq3gz4j4lne6cp5b@phikpenjras3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52qapxj7sdearduro3iiqqpekrltc5zviwgq3gz4j4lne6cp5b@phikpenjras3> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi Bjorn, On Thu, Jun 22, 2023 at 02:43:07PM -0700, Bjorn Andersson wrote: > On Thu, Jun 22, 2023 at 03:40:19PM -0400, Adrien Thierry wrote: > > The downstream driver [1] implements set_suspend(), which deals with > > both runtime and system sleep/resume. The upstream driver already has > > runtime PM ops, so add the system sleep PM ops as well, reusing the same > > code as the runtime PM ops. > > > > [1] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/phy/phy-msm-snps-hs.c > > > > Signed-off-by: Adrien Thierry > > --- > > drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 18 ++++++++++-------- > > 1 file changed, 10 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c > > index ce1d2f8b568a..378a5029f61e 100644 > > --- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c > > +++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c > > @@ -179,7 +179,7 @@ static inline void qcom_snps_hsphy_write_mask(void __iomem *base, u32 offset, > > readl_relaxed(base + offset); > > } > > > > -static int qcom_snps_hsphy_suspend(struct qcom_snps_hsphy *hsphy) > > +static int qcom_snps_hsphy_do_suspend(struct qcom_snps_hsphy *hsphy) > > { > > dev_dbg(&hsphy->phy->dev, "Suspend QCOM SNPS PHY\n"); > > > > @@ -199,7 +199,7 @@ static int qcom_snps_hsphy_suspend(struct qcom_snps_hsphy *hsphy) > > return 0; > > } > > > > -static int qcom_snps_hsphy_resume(struct qcom_snps_hsphy *hsphy) > > +static int qcom_snps_hsphy_do_resume(struct qcom_snps_hsphy *hsphy) > > { > > int ret; > > > > @@ -214,25 +214,25 @@ static int qcom_snps_hsphy_resume(struct qcom_snps_hsphy *hsphy) > > return 0; > > } > > > > -static int __maybe_unused qcom_snps_hsphy_runtime_suspend(struct device *dev) > > +static int __maybe_unused qcom_snps_hsphy_suspend(struct device *dev) > > { > > struct qcom_snps_hsphy *hsphy = dev_get_drvdata(dev); > > > > if (!hsphy->phy_initialized) > > return 0; > > > > - qcom_snps_hsphy_suspend(hsphy); > > + qcom_snps_hsphy_do_suspend(hsphy); > > return 0; > > } > > > > -static int __maybe_unused qcom_snps_hsphy_runtime_resume(struct device *dev) > > +static int __maybe_unused qcom_snps_hsphy_resume(struct device *dev) > > { > > struct qcom_snps_hsphy *hsphy = dev_get_drvdata(dev); > > > > if (!hsphy->phy_initialized) > > return 0; > > > > - qcom_snps_hsphy_resume(hsphy); > > + qcom_snps_hsphy_do_resume(hsphy); > > return 0; > > } > > > > @@ -518,8 +518,10 @@ static const struct of_device_id qcom_snps_hsphy_of_match_table[] = { > > MODULE_DEVICE_TABLE(of, qcom_snps_hsphy_of_match_table); > > > > static const struct dev_pm_ops qcom_snps_hsphy_pm_ops = { > > - SET_RUNTIME_PM_OPS(qcom_snps_hsphy_runtime_suspend, > > - qcom_snps_hsphy_runtime_resume, NULL) > > + SET_RUNTIME_PM_OPS(qcom_snps_hsphy_suspend, > > + qcom_snps_hsphy_resume, NULL) > > + SET_SYSTEM_SLEEP_PM_OPS(qcom_snps_hsphy_suspend, > > + qcom_snps_hsphy_resume) > > Won't this cause issues if you system suspend the device while it's > already runtime suspended? > I'm not sure if it would cause issues, but after reflexion and discussion with Andrew, I think it's unnecessary to add system PM ops in the femto PHY driver. In the dwc3 core, both system and runtime suspend end up calling dwc3_suspend_common(). From there, what happens depends on the USB mode and whether the controller is entering system or runtime suspend. HOST mode: (1) system suspend on a non-wakeup controller The [1] if branch is taken. dwc3_core_exit() is called, which ends up calling phy_power_off() and phy_exit(). Those two functions decrease the PM runtime count at some point, so they will trigger the PHY runtime sleep (assuming the count is right). (2) runtime suspend / system suspend on a wakeup controller The [1] branch is not taken. dwc3_suspend_common() calls phy_pm_runtime_put_sync(dwc->usb2_generic_phy). Assuming the ref count is right, the PHY runtime suspend op is called. DEVICE mode: dwc3_core_exit() is called on both runtime and system sleep unless the controller is already runtime suspended. OTG mode: (1) system suspend : dwc3_core_exit() is called (2) runtime suspend : do nothing With that in mind: 1) Does the PHY need to implement system sleep callbacks? dwc3 core system sleep callback will already runtime suspend the PHY, and also call phy_power_off() and phy_exit() for non-wakeup controllers. So, adding system PM ops to the femto PHY driver would be redundant. 2) Should the ref_clk be disabled for runtime sleep / wakeup controller system sleep, or only for non-wakeup controller system sleep? I'm a little hesitant here. In my submission I'm disabling it in both, but looking at the downstream code you provided, it seems it's only disabled for system sleep. ref_clk is disabled by phy->set_suspend() [2] which IIUC is only called in the system sleep path through dwc3_core_exit() [3]. Moreover, in host mode the upstream code seems to make a distinction between 1) runtime sleep / system sleep for wakeup controller, and 2) system sleep for non-wakeup controller where phy_power_off() and phy_exit() are only called in the latter. This suggests the PHY is not supposed to be in a fully powered-off state for runtime sleep and system sleep for wakeup controller. So, it's possible the ref_clk should be kept enabled in this case. What is your take on this? I could only disable ref_clk in the femto phy->exit() callback to keep ref_clk enabled during runtime sleep and make sure it's only disabled on system sleep for non-wakeup controller. Hoping I'm not missing anything here. Best, Adrien [1] https://elixir.bootlin.com/linux/latest/source/drivers/usb/dwc3/core.c#L1988 [2] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/phy/phy-msm-snps-hs.c#L524 [3] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/LV.AU.1.2.1.r2-05300-gen3meta.0/drivers/usb/dwc3/core.c#L1915 > Regards, > Bjorn > > > }; > > > > static void qcom_snps_hsphy_override_param_update_val( > > -- > > 2.40.1 > >