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 06F9436B; Tue, 21 Oct 2025 15:39:41 +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=1761061182; cv=none; b=SJe4OkWehLh0aWEkETRxli953oc7QdqDHZ5zVVlevKNruMLZRWG3/PiwyMe9bbZasyvX7EiHhVbM4DHckBhn4c2x562eGwrHloiQkWJ+B7fAVIGqIZeT2mQ1UlfI3Ezy8k3CNbe47R5yv5U2fS6bwat+qqb7FVUwvpuEw4UBSD4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761061182; c=relaxed/simple; bh=W0p8yKBOrvMdn62s9c+gjIicRjtIrALhyyoPoabEaio=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=AsxT0MsX9ik2CaFvGM28limhcrn5jMn6dqMrGIrBZxuMw2imy/2ivchNXUpNQEa79eAmaNUvNskjHX08N+pYaUya9REbmtXNpbYYnBFX57DKkjyvLIZm7AnbqN15E+9j4DVlzmyN/i/yuBajwbexcQqymZ+CBSor1ynpal5EngQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PniYtRQB; 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="PniYtRQB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 681EFC4CEF1; Tue, 21 Oct 2025 15:39:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761061181; bh=W0p8yKBOrvMdn62s9c+gjIicRjtIrALhyyoPoabEaio=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=PniYtRQBqYICq0hnLKFG2Bx/lH1zymTiPaTxPNp5xY1OG9o+vC4DTpekul9HuLqON be1U8/T5RwnL+f38i6gGleTtu7d32+cY1J/+hYtn8YC7y1Wil4h2EShFTZv4CatMFl btlC3eI7if0H13dibulg+/b5nqmi5EVmGlYnYWiyk1K8oiCpx0H2WylOcU1SqEd1yn oHnP8bRRPS8zQeKbyIrG04FFKC+zaPIHvcHtG07BJIDLO1HLV+VI0jMlxSvPBaBlRu N8BGWUgragKKHTpQHIH6FR6XLRObjMCKnwd2A3UMjLnnSylkAltze797WjwlsPf/fT bZhq0LuWGv+LA== Date: Tue, 21 Oct 2025 10:39:40 -0500 From: Bjorn Helgaas To: Manivannan Sadhasivam Cc: Manivannan Sadhasivam , Christian Zigotzky , FUKAUMI Naoki , linux-rockchip@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH] PCI/ASPM: Enable only L0s and L1 for devicetree platforms Message-ID: <20251021153940.GA1191128@bhelgaas> 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: <2wv7662f23seqtifn4zkud6xlecfhpeso4rn72syn6q2ts6sm5@cllw6gyv2xwx> On Tue, Oct 21, 2025 at 06:05:07PM +0530, Manivannan Sadhasivam wrote: > On Tue, Oct 21, 2025 at 09:31:32AM +0530, Manivannan Sadhasivam wrote: > > On Mon, Oct 20, 2025 at 05:12:07PM -0500, Bjorn Helgaas wrote: > > > + if (link->aspm_support & PCIE_LINK_STATE_L0S) > > > + link->aspm_default |= PCIE_LINK_STATE_L0S; > > > + if (link->aspm_support & PCIE_LINK_STATE_L1) > > > + link->aspm_default |= PCIE_LINK_STATE_L1; > > > > Not sure if it is worth setting these states conditionally. Link > > state enablement code should make use of the cached ASPM cap in > > 'link->aspm_capable'. > > I see the point now. Without the check, we falsely claim that the > ASPM states are getting enabled. But we cannot be sure until the > register write to LNKCTL happens, which will depend on many factors > (own device capability, upstream/downstream port capability,...) > > To avoid ambiguity, can we reword the log to something like, > > "ASPM: Overridding default states %s%s\n" I think aspm_support already includes the capabilities from both ends of the link: if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L0S) link->aspm_support |= PCIE_LINK_STATE_L0S; if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L1) link->aspm_support |= PCIE_LINK_STATE_L1;