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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1EC22CCF9F8 for ; Wed, 5 Nov 2025 10:28:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=qLaE+coW8iQvWs9DFaPWmc1/BtPrNgQSYqVTfqyMrC4=; b=fdXCrV+14LinwCgx5+CcFSshd4 4V0Dqm7lHnA1sdCqlci2mTR5PjUUudQYM0/DNC3kkLdQYamPh2gmmERQFwAfjndr4hcUw7qyhk0an LNF8EQDV0I3U/FPqqBuQyhvj50NiNK1vZl6pSfPymY+U0a5354GHNJd6lUQe8DZjooJumrZfzguh2 iCGJUTnrn+9tiM3lApcBreBTRqONLUAbjiD1i27bk7N2bFW9FT32utMYBb71qzLuQdyjs5Buh//oZ GrGIvYq07spf4LwQLiKNIcq2IpN5Qqc7j3qHwO8MGCoG9106xYiaBPXG9I7qYOE/Nv6nDBWYPnwRs nRBWtrfQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGakR-0000000DTGE-1pzW; Wed, 05 Nov 2025 10:28:15 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGakP-0000000DTFg-0AAO for linux-arm-kernel@lists.infradead.org; Wed, 05 Nov 2025 10:28:14 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 1C31044074; Wed, 5 Nov 2025 10:28:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 271F4C4CEF8; Wed, 5 Nov 2025 10:28:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762338491; bh=sATlqbfCMquHAhiGt98UAjhO81tc66fm/b5s3xZ+bT0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aVk2cw91xb3rYUDPFcGEtjuOOgvOL7LPdFKi9Ek3C8A3pJKShz5NSz1ygG7990U70 5MKPxs/CwWggCZ4NBUoVASSOYENYZskX4+KO9mC8L1RewpnSZj56X8WFBZDNFPpUfy YCNph4JFxwP9Up1f+JrWSvK82fQiSY22vGOxTCP6iLTvLpbHlddw5Nn4D6qLqZDe18 A0Oj6TSleOyym73rw53E1sx7OYY8l/oHNN3z842GkfoKpnsiK0i2CxbV/gyf2DmldO cFy/IYkMMWOVXppMcDDu5pu2Fn3ak95UF3m2BmecxYlu57lWhbPod+Xmu+3QfoThOH 18Og5nj9EJS4w== Date: Wed, 5 Nov 2025 11:28:04 +0100 From: Niklas Cassel To: Vincent Guittot Cc: Bjorn Helgaas , chester62515@gmail.com, mbrugger@suse.com, ghennadi.procopciuc@oss.nxp.com, s32@nxp.com, bhelgaas@google.com, jingoohan1@gmail.com, lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, Ionut.Vicovan@nxp.com, larisa.grigore@nxp.com, Ghennadi.Procopciuc@nxp.com, ciprianmarian.costea@nxp.com, bogdan.hamciuc@nxp.com, Frank.li@nxp.com, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev Subject: Re: [PATCH 3/4 v3] PCI: s32g: Add initial PCIe support (RC) Message-ID: References: <20251022174309.1180931-4-vincent.guittot@linaro.org> <20251022190402.GA1262472@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251105_022813_094058_FB9BAB6B X-CRM114-Status: GOOD ( 15.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Oct 24, 2025 at 08:50:46AM +0200, Vincent Guittot wrote: > On Wed, 22 Oct 2025 at 21:04, Bjorn Helgaas wrote: > > > + dw_pcie_dbi_ro_wr_en(pci); > > > + > > > + val = dw_pcie_readl_dbi(pci, PCIE_PORT_FORCE); > > > + val |= PORT_FORCE_DO_DESKEW_FOR_SRIS; > > > + dw_pcie_writel_dbi(pci, PCIE_PORT_FORCE, val); > > > + > > > + /* > > > + * Set max payload supported, 256 bytes and > > > + * relaxed ordering. > > > + */ > > > + val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL); > > > + val &= ~(PCI_EXP_DEVCTL_RELAX_EN | > > > + PCI_EXP_DEVCTL_PAYLOAD | > > > + PCI_EXP_DEVCTL_READRQ); > > > + val |= PCI_EXP_DEVCTL_RELAX_EN | > > > + PCI_EXP_DEVCTL_PAYLOAD_256B | > > > + PCI_EXP_DEVCTL_READRQ_256B; > > > + dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val); > > > > MPS and relaxed ordering should be configured by the PCI core. Is > > there some s32g-specific restriction about these? > > I will check with the team why they did that Most likely, the reason is that, the PCI core does not set the MPS to the maximum supported MPS for the root port. So without that change, the port will use use 128B instead of 256B. I assume that you should be able to drop (at least the MPS part) if this change gets accepted: https://lore.kernel.org/linux-pci/20251104165125.174168-1-18255117159@163.com/ Kind regards, Niklas