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 0F81ECA1005 for ; Tue, 2 Sep 2025 08:52:22 +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=Hqr2PkWeqj78bgEo/ix/HnyM3/D2QqFTKb1SDJ42Iko=; b=mLToLw0Qfn/8ZvQN/Ktof6irZ3 mk45QDo3MxhiUc5A7i52FuP3ybFWMgS1MM7h9LXII5dc3lwVzDBQneODkcBABn5ptF+ONYpiXvCqk Rws1QNFKBc5u43vPJD+QpP136wYAIRq5OJra0PSFptaKgEn0pM2wdiJ26m/h2wKhAwNGw4hfJ7Dzx 9OKJlQ+1fIvaP7CqRhK87h7E4OqRgIG6B7j+TPO7KKogP4JXIINnubjH3yd7/MUn747hdM+mJlhKe eLQ+UsPaN6dERfWUJR/1P+ZGQRxTJO9XhY9TSSUkGYL04zzI7sTtNJJm6Pxp7jz3e3tU032QdTKLk 0skE4n8g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1utMkT-0000000GBlE-0Dhh; Tue, 02 Sep 2025 08:52:17 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1utMSB-0000000G4Qu-2dDX; Tue, 02 Sep 2025 08:33:23 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 00DD460210; Tue, 2 Sep 2025 08:33:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC295C4CEF7; Tue, 2 Sep 2025 08:33:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756802002; bh=Hqr2PkWeqj78bgEo/ix/HnyM3/D2QqFTKb1SDJ42Iko=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eexVNZZOyCZ752U7B0Hxcl7iDb0v3eqNyGVNEJNzf0PCN5A3mrQ0AScJt5LA06Hf8 a5sf4rqTHCA59xQlkbFYGFgseE5b3iaP3LEVm/20ZJspA8j5cy22VIF+SVI9igcSgz 0UlRax8yYiV6MUzZXJbGEAZWizY2Zbj39kpJnvfo8/I0NyNYCiVGbUpt2+IQaDmq0L vc9Y3Prxj+tY0TBlksdY/5gts7JPJHy/mZCpxdYkUbWOgVxD7JuiK6wKZJbtvOYKwk qPcfUTqYDxqxCBibyub+dc0VK8JsdVpshCG+MpMFB7DMdDvni4nEY0L6G7UG+G/O6F AgY1n5wtbq6Aw== Date: Tue, 2 Sep 2025 10:33:16 +0200 From: Niklas Cassel To: Hans Zhang <18255117159@163.com> Cc: lpieralisi@kernel.org, kwilczynski@kernel.org, bhelgaas@google.com, heiko@sntech.de, mani@kernel.org, yue.wang@amlogic.com, pali@kernel.org, neil.armstrong@linaro.org, robh@kernel.org, jingoohan1@gmail.com, khilman@baylibre.com, jbrunet@baylibre.com, martin.blumenstingl@googlemail.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH v5 0/2] Configure root port MPS during host probing Message-ID: References: <20250620155507.1022099-1-18255117159@163.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250620155507.1022099-1-18255117159@163.com> 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, Jun 20, 2025 at 11:55:05PM +0800, Hans Zhang wrote: > Current PCIe initialization exhibits a key optimization gap: Root Ports > may operate with non-optimal Maximum Payload Size (MPS) settings. While > downstream device configuration is handled during bus enumeration, Root > Port MPS values inherited from firmware or hardware defaults often fail > to utilize the full capabilities supported by controller hardware. This > results in suboptimal data transfer efficiency throughout the PCIe > hierarchy. (snip) Gentle ping.