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 482C8C001E0 for ; Wed, 2 Aug 2023 16:31:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230489AbjHBQbn (ORCPT ); Wed, 2 Aug 2023 12:31:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230352AbjHBQbm (ORCPT ); Wed, 2 Aug 2023 12:31:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E264210D; Wed, 2 Aug 2023 09:31:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1AC7A6199A; Wed, 2 Aug 2023 16:31:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 347FDC433C8; Wed, 2 Aug 2023 16:31:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690993900; bh=0lpVhKDUd7Tnt1pOBSUzHZtuD1Oebkn4+PkPwpT2kKs=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=j0r8Vw0e00dzFIZouvGCpEl3w6wxJOtu5r+oKgbEEIllcsLcOgwkF+oW74VmuJJBr gXosxOrbTcwzjl6Ri2+Vpvwaj+dLrnCki/kBmQADQLYHTqjK1iBIe0nH+4h3waSf4r M5D19Z0MEPM1/zXyX7/FVkLek5okoT7aKTw3f7d3T0A6x3xJp4N5+9kQoMj3Om7XEg o4mGK6UbzNe388NZKfrgdLIRcayKsqL+xqLQhVUYoEmA3lv84UP4bfn656s9Lv9ldl QzrI/ZsQwszGGQoAl5MCHtteyeekqY7TOFtRf2V5B13p4QR5qccuN6FUyqNfPADYIn dtQWeEO7uAhyA== Date: Wed, 2 Aug 2023 11:31:38 -0500 From: Bjorn Helgaas To: Frank Li Cc: mani@kernel.org, bhelgaas@google.com, devicetree@vger.kernel.org, gustavo.pimentel@synopsys.com, imx@lists.linux.dev, kw@linux.com, leoyang.li@nxp.com, linux-arm-kernel@lists.infradead.org, linux-imx@nxp.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, lorenzo.pieralisi@arm.com, lpieralisi@kernel.org, manivannan.sadhasivam@linaro.org, minghuan.lian@nxp.com, mingkai.hu@nxp.com, robh+dt@kernel.org, roy.zang@nxp.com, shawnguo@kernel.org, zhiqiang.hou@nxp.com Subject: Re: [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Message-ID: <20230802163138.GA61043@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230802155748.212377-1-Frank.Li@nxp.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Wed, Aug 02, 2023 at 11:57:47AM -0400, Frank Li wrote: > Introduce helper function dw_pcie_get_ltssm to retrieve SMLH_LTSS_STATE. s/dw_pcie_get_ltssm/dw_pcie_get_ltssm()/ > Add callback .pme_turn_off and .exit_from_l2 for platform specific PME > handling. > > Add common dw_pcie_suspend(resume)_noirq() API to avoid duplicated code > in dwc pci host controller platform driver. > > Typical L2 entry workflow/dw_pcie_suspend_noirq() > > 1. Transmit PME turn off signal to PCI devices and wait for PME_To_Ack. > 2. Await link entering L2_IDLE state. > > Typical L2 exit workflow/dw_pcie_resume_noirq() > > 1. Issue exit from L2 command. > 2. Reinitialize PCI host. > 3. Wait for link to become active. > > Signed-off-by: Frank Li > --- > Change from v6 to v7 > - change according to Manivannan's comments. > fix sleep value 100 (should be 1000 for 1ms). > + * PCI Express Base Specification Rev 4.0 Section 5.3.3.2.1 PME > + * Synchronization Recommends 1ms to 10ms timeout to check L2 ready. > + */ > + ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > + 1000, 10000, false, pci); Thanks for the spec citation. Can you please reference the current spec, i.e., "PCIe r6.0, sec 5.3.3.2.1". s/Recommends/recommends/ It would really be great to have a #define for this since the bare numbers are not very meaningful and they're not specific to DWC so a #define would let us find similar situations in other drivers. Bjorn