From patchwork Mon Apr 29 19:18:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Helgaas X-Patchwork-Id: 13647583 X-Patchwork-Delegate: bhelgaas@google.com 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 7471B13AA45; Mon, 29 Apr 2024 19:18:30 +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=1714418311; cv=none; b=qzrOk+dA9yWyTtSmwqug0roWRu6Js+a1VXS8CaIROfG71OmkM0YHibWNDiBvMREIw84/ArsaFcA2eaV/HR/Pn5yVo7J894MKP7Z+Khp8RW3NSnzpfxRauaB1bPkplO0ucCCgN5mndkFDVwyAv/evuTx1Y4Zz0gUv7XEQFkknB9E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714418311; c=relaxed/simple; bh=AhghYKrrM38h4mEYYi+e56vFeWtbc58kF0yKtXHD/ds=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=XgaarvWKqWUbypchYhMjmH1ePSNYAikokNpp72I9pHhunAw62WtXea1Ks9tqUaCPLiiiWSEimgf61HbI7SJQ+sFViAG2eh1I1WHLHKIT2TcO1pXcFIR0P9dsAj7zMCGvWqMcSjxHMnwzP+XOLgb0/eCHs0aHzZsPGAiXOPP65I8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vP8DH5Ap; 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="vP8DH5Ap" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06907C113CD; Mon, 29 Apr 2024 19:18:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714418310; bh=AhghYKrrM38h4mEYYi+e56vFeWtbc58kF0yKtXHD/ds=; h=From:To:Cc:Subject:Date:From; b=vP8DH5Ap0xqqbMYT+95FrpoJBZrUXrgMUmjEqkFa+xmeOEvFKc9Cz8fOIOyTBjxsY ZK+TsMqnA4cXYz1JuoYM95bEwk51KUgnNsKJlOwsBG2gHjV5X13wjkpXY+btTzGbY3 7m5gsfuMXHf85566atJi4POPgx8Hc+UaAFps8OCsGNT9A9Bf7Wrfi1UCKX5JerEM4k GPw1HJmqjaWq/wcRXKRwM7Wv4ulAVZU3DDEI0hjnyPIMRkJJV8t7f8bAYgWURBtj8U juN3ZOjc02ewfhy82I5rYGJnSH6OR9rn/BHGVH3451OdcemmjsWcXGA5qImaXUNDhw oJ1/H+M0ydoDg== From: Bjorn Helgaas To: linux-pci@vger.kernel.org Cc: Vidya Sagar , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , "Maciej W . Rozycki" , "David E . Box" , Johan Hovold , Heiner Kallweit , Ajay Agarwal , linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: [PATCH] PCI/ASPM: Clarify that pcie_aspm=off means leave ASPM untouched Date: Mon, 29 Apr 2024 14:18:21 -0500 Message-Id: <20240429191821.691726-1-helgaas@kernel.org> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Bjorn Helgaas Previously we claimed "pcie_aspm=off" meant that ASPM would be disabled, which is wrong. Correct this to say that with "pcie_aspm=off", Linux doesn't touch any ASPM configuration at all. ASPM may have been enabled by firmware, and that will be left unchanged. See "aspm_support_enabled". Signed-off-by: Bjorn Helgaas Reviewed-by: David E. Box --- Documentation/admin-guide/kernel-parameters.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bb884c14b2f6..4bc281d6e8d3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4590,9 +4590,10 @@ norid [S390] ignore the RID field and force use of one PCI domain per PCI function - pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power + pcie_aspm= [PCIE] Forcibly enable or ignore PCIe Active State Power Management. - off Disable ASPM. + off Don't touch ASPM configuration at all. Leave any + configuration done by firmware unchanged. force Enable ASPM even on devices that claim not to support it. WARNING: Forcing ASPM on may cause system lockups.