From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44BEB2E9EB2; Tue, 2 Sep 2025 08:33:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756802003; cv=none; b=chjKQwMMS1B1nCGdUmZVs5NkyJnSz7UCldlwATtiD+aF2b7O1PLBBQ121BKJcrzplKsNETs+hOeDyl1p4Q09cxsSzA63XlLI1HHNeVaDxPTAJWn0kyJhUSEwYrekNwnbP9zP+sp2VroMEyddtjeLhGa81Kh7uCprwlD29kWK2Rw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756802003; c=relaxed/simple; bh=Hqr2PkWeqj78bgEo/ix/HnyM3/D2QqFTKb1SDJ42Iko=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d5kYoeXZFX/QTE4Kq3SduV8i6zRqM77u8p29JiA4ReZJRrCgWPvv08LnIZV1p1Yw0PQ82uz9AnCYyWoAK9pwNaybUiDtmFP36vRA9OCKg4aMNCqXgkDaOtXYVad4KBcTI6nIXUlTuY7S4uRS07qmhvoekgsHieMy039QaNHMLs4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eexVNZZO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eexVNZZO" 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> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250620155507.1022099-1-18255117159@163.com> 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.