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 10B00C4167B for ; Thu, 30 Nov 2023 16:51:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232382AbjK3QvJ (ORCPT ); Thu, 30 Nov 2023 11:51:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235171AbjK3QvG (ORCPT ); Thu, 30 Nov 2023 11:51:06 -0500 Received: from mail-qt1-x82c.google.com (mail-qt1-x82c.google.com [IPv6:2607:f8b0:4864:20::82c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F81010FF for ; Thu, 30 Nov 2023 08:51:12 -0800 (PST) Received: by mail-qt1-x82c.google.com with SMTP id d75a77b69052e-41cd97d7272so6738601cf.0 for ; Thu, 30 Nov 2023 08:51:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1701363071; x=1701967871; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=utw4KTuk3SE3y1D2yo/rUQfAbbyptZOivZr+Lu23J1Q=; b=s3lDIpU4ZslyYJA40bcye3JGJKwYGx+ApO2ie7Ij+OqFR2hRvCZlyw0n6oOaHuT0HG +g84gB8DNbYhRXaxzO0+4gFvpUSmWljw3tD0j7ITPTgKg6yJMNWaGsU9nApr651dIjfo dnPaAzZsUsgUuXt2++RKiUOumuoKb40qN1TGRw3FY3/hYeshf0FllcdSAw4pxaYdOML4 CTD1ovhh11v0rO+uOKRfiOC+qTmudiqhT9u7+LXLzUBhJVEqQ+OiDQYKTvgM+QR7irJY 1SNEbnv5q+ZFRSaHmPdhbwCNKEayL99h4HQGTFajaMl++vO2Wqoj//o90Cw+9ZXh8knN H2Rg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701363071; x=1701967871; h=in-reply-to:content-transfer-encoding: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=utw4KTuk3SE3y1D2yo/rUQfAbbyptZOivZr+Lu23J1Q=; b=lgW8DYbStPMMk9h4kG5LHQRJT+66pbF9uKvCxYoWo6i54ob5N4oo/XpspjB2vWtJS/ 8x9CdRCwo4KDeq+HYTTkucxYYasPr8iwbVsQGNEOtHnWXgyT4qfNVAqas6egUTuodkV7 UE+6YtQcDRx8hE+tCIznQiUJd1o6D4Oc6VAnSEn/RrrSKHKipX3hUY2tYVwSD/t+1T81 cy6kxKgtlkqgvgg78cA5fvbJT0ypohhS4Qd64mVo/vQ2wjeXoMwuwBS8qafB8ItpzrN7 gG9tSXN4qOYP8nnQBm0dDTFAKEWiiqOELKFX2JVaHMXipKIUX7Zo3qxrLTsEqjFH31kY 7yPA== X-Gm-Message-State: AOJu0YwJ5HgIxPw4OHOBFx09qkq3iqfxJcTuGzPyaJGJNhVvBglbFbQ+ 2jKb8MSRJIz7qUPS1hOK/VdL X-Google-Smtp-Source: AGHT+IERXWT08jVAe9ZbWDR/pNrAJrgo4gr7lr9NP15/wA+iYSlr52t4YrQ+Anua7VoZTtf/uwzbgA== X-Received: by 2002:ad4:4c07:0:b0:67a:2bbe:a02a with SMTP id bz7-20020ad44c07000000b0067a2bbea02amr18478142qvb.57.1701363071661; Thu, 30 Nov 2023 08:51:11 -0800 (PST) Received: from thinkpad ([117.213.102.92]) by smtp.gmail.com with ESMTPSA id y2-20020a0cd982000000b0067a34deb15asm649952qvj.9.2023.11.30.08.51.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Nov 2023 08:51:11 -0800 (PST) Date: Thu, 30 Nov 2023 22:21:00 +0530 From: Manivannan Sadhasivam To: Frank Li Cc: bhelgaas@google.com, imx@lists.linux.dev, kw@linux.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, lpieralisi@kernel.org, minghuan.Lian@nxp.com, mingkai.hu@nxp.com, robh@kernel.org, roy.zang@nxp.com Subject: Re: [PATCH v4 4/4] PCI: layerscape: Add suspend/resume for ls1043a Message-ID: <20231130165100.GV3043@thinkpad> References: <20231129214412.327633-1-Frank.Li@nxp.com> <20231129214412.327633-5-Frank.Li@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20231129214412.327633-5-Frank.Li@nxp.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 29, 2023 at 04:44:12PM -0500, Frank Li wrote: > In the suspend path, PME_Turn_Off message is sent to the endpoint to > transition the link to L2/L3_Ready state. In this SoC, there is no way to > check if the controller has received the PME_To_Ack from the endpoint or > not. So to be on the safer side, the driver just waits for > PCIE_PME_TO_L2_TIMEOUT_US before asserting the SoC specific PMXMTTURNOFF > bit to complete the PME_Turn_Off handshake. This link would then enter > L2/L3 state depending on the VAUX supply. > > In the resume path, the link is brought back from L2 to L0 by doing a > software reset. > Same comment on the patch description as on patch 2/4. > Signed-off-by: Frank Li > --- > > Notes: > Change from v3 to v4 > - Call scfg_pcie_send_turnoff_msg() shared with ls1021a > - update commit message > > Change from v2 to v3 > - Remove ls_pcie_lut_readl(writel) function > > Change from v1 to v2 > - Update subject 'a' to 'A' > > drivers/pci/controller/dwc/pci-layerscape.c | 63 ++++++++++++++++++++- > 1 file changed, 62 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c > index 590e07bb27002..d39700b3afaaa 100644 > --- a/drivers/pci/controller/dwc/pci-layerscape.c > +++ b/drivers/pci/controller/dwc/pci-layerscape.c > @@ -41,6 +41,15 @@ > #define SCFG_PEXSFTRSTCR 0x190 > #define PEXSR(idx) BIT(idx) > > +/* LS1043A PEX PME control register */ > +#define SCFG_PEXPMECR 0x144 > +#define PEXPME(idx) BIT(31 - (idx) * 4) > + > +/* LS1043A PEX LUT debug register */ > +#define LS_PCIE_LDBG 0x7fc > +#define LDBG_SR BIT(30) > +#define LDBG_WE BIT(31) > + > #define PCIE_IATU_NUM 6 > > struct ls_pcie_drvdata { > @@ -225,6 +234,45 @@ static int ls1021a_pcie_exit_from_l2(struct dw_pcie_rp *pp) > return scfg_pcie_exit_from_l2(pcie->scfg, SCFG_PEXSFTRSTCR, PEXSR(pcie->index)); > } > > +static void ls1043a_pcie_send_turnoff_msg(struct dw_pcie_rp *pp) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > + struct ls_pcie *pcie = to_ls_pcie(pci); > + > + scfg_pcie_send_turnoff_msg(pcie->scfg, SCFG_PEXPMECR, PEXPME(pcie->index)); > +} > + > +static int ls1043a_pcie_exit_from_l2(struct dw_pcie_rp *pp) > +{ > + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); > + struct ls_pcie *pcie = to_ls_pcie(pci); > + u32 val; > + > + /* > + * Only way let PEX module exit L2 is do a software reset. Can you expand PEX? What is it used for? Also if the reset is only for the PEX module, please use the same comment in both patches 2 and 4. Patch 2 doesn't mention PEX in the comment. - Mani > + * LDBG_WE: allows the user to have write access to the PEXDBG[SR] for both setting and > + * clearing the soft reset on the PEX module. > + * LDBG_SR: When SR is set to 1, the PEX module enters soft reset. > + */ > + val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG); > + val |= LDBG_WE; > + ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val); > + > + val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG); > + val |= LDBG_SR; > + ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val); > + > + val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG); > + val &= ~LDBG_SR; > + ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val); > + > + val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG); > + val &= ~LDBG_WE; > + ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val); > + > + return 0; > +} > + > static const struct dw_pcie_host_ops ls_pcie_host_ops = { > .host_init = ls_pcie_host_init, > .pme_turn_off = ls_pcie_send_turnoff_msg, > @@ -242,6 +290,19 @@ static const struct ls_pcie_drvdata ls1021a_drvdata = { > .exit_from_l2 = ls1021a_pcie_exit_from_l2, > }; > > +static const struct dw_pcie_host_ops ls1043a_pcie_host_ops = { > + .host_init = ls_pcie_host_init, > + .pme_turn_off = ls1043a_pcie_send_turnoff_msg, > +}; > + > +static const struct ls_pcie_drvdata ls1043a_drvdata = { > + .pf_lut_off = 0x10000, > + .pm_support = true, > + .scfg_support = true, > + .ops = &ls1043a_pcie_host_ops, > + .exit_from_l2 = ls1043a_pcie_exit_from_l2, > +}; > + > static const struct ls_pcie_drvdata layerscape_drvdata = { > .pf_lut_off = 0xc0000, > .pm_support = true, > @@ -252,7 +313,7 @@ static const struct of_device_id ls_pcie_of_match[] = { > { .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata }, > { .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata }, > { .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata }, > - { .compatible = "fsl,ls1043a-pcie", .data = &ls1021a_drvdata }, > + { .compatible = "fsl,ls1043a-pcie", .data = &ls1043a_drvdata }, > { .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata }, > { .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata }, > { .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata }, > -- > 2.34.1 > -- மணிவண்ணன் சதாசிவம்