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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 31A4ACCD1BC for ; Thu, 23 Oct 2025 18:25:32 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4csvbZ5H7Hz3bf4; Fri, 24 Oct 2025 05:25:30 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2600:3c04:e001:324:0:1991:8:25" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1761243930; cv=none; b=RVKSyvSIVNynLj+ZY5Qivc5yWElIdcHIMZayZKsXU257kMmdwhPiq2eK1JJpAC1Ile1VhZdcy5vUxWZTzrQyO/fTL1bhpEJ5R9Q5cYKxC5pgZrjE3nQjzJ1oXPlHfqN799Ile1mil1fL9y6MJzLqS3yg/kUH0j7b2XsVV+e8f7EcZkXAsT0R4GrX9UvJ8A/7WIKaROf/jCYDBpZAynXnL0Sc7toxQwd8im11jkWaiUEFzznVJ/nay/AKpkB5ktSDThX7dGWO+MQE9RWxI68Npt2tUtIHbITBqal+EMJHPb8weBBz8XgCZ+xrCFEVWp9bmCSEBpYcvL3X2pHPpSSgwg== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1761243930; c=relaxed/relaxed; bh=4+62wyTCJyLAiYIDQNu3kvnegWQcawElkeVEBVHKlDM=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=dkr9a1VlY2QZP8y/6uOsGOaVJSg81WcgYivy0fcQfm+/Qr/t1zJf3X0uPKzbUVxQc6XkTTdvIn4gFB5FhSxZdmOr0L8bnCZ2xgEzcZKxKwy2yGqilE8MJmD2fBHqjy0JWtFVCimrUgqHWC/D3HfM8pDT5FmxTxi6ITfh+wcKshRDmK4/tqVsp1s6zaL+/p+D0NI6Tf9hZhLbijEKNua/u1ZfnuSIW8F8zQlWhGzgjpMjsCqjo5ItM5DHYr65gEjGyuTXBohUMZs6R22slLBzLM2HEttha5xTsydJwuPtN3Zqkpns20YqtVVNGAOF9QX5Bmx291LY8JDW5IC08e+h4Q== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=o3bQddqm; dkim-atps=neutral; spf=pass (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=helgaas@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=o3bQddqm; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=helgaas@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [IPv6:2600:3c04:e001:324:0:1991:8:25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4csvbY5H0bz3bd0 for ; Fri, 24 Oct 2025 05:25:29 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 3C9EA61185; Thu, 23 Oct 2025 18:25:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C23F9C4CEE7; Thu, 23 Oct 2025 18:25:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761243926; bh=mOBvJWsTb0vY1iyFfVuyBlLeVYQAHWLsWjtUccN/ADA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=o3bQddqmlEUkUHxUG3lxTANhdQ3CzljYSwNiZ+aw9PrwVxuPEQ1VK1NjH6lSPvVgj qYmBKwvUS0H/uIkSkZ/SxY1ue9eAEA+RHhnIhfII0JqwYt7whu4wIC0UAnoEvXkJmR xYH77ZXgLn00Q+kGapHy5q1qyteK081AOWetYP5XE270E36LWDnEgRHAcyKV5ivYYz 10KMcwk98UI4QGwgIXVTzHtRQZI8BxHglr31GuDXx6XHYRNGzM4NnnAl1Rpunvg6gl CSfbS5ZdJRzisTbKkDo8ORXc/RZjiUWxCpgYfKqPDscSeSsaBxrf72IDO2M+9o2+02 74WzG/ZfLnP/g== Date: Thu, 23 Oct 2025 13:25:25 -0500 From: Bjorn Helgaas To: linux-pci@vger.kernel.org Cc: Manivannan Sadhasivam , Christian Zigotzky , FUKAUMI Naoki , Herve Codina , Diederik de Haas , Dragan Simic , linuxppc-dev@lists.ozlabs.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH] PCI/ASPM: Enable only L0s and L1 for devicetree platforms Message-ID: <20251023182525.GA1306699@bhelgaas> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251023180645.1304701-1-helgaas@kernel.org> On Thu, Oct 23, 2025 at 01:06:26PM -0500, Bjorn Helgaas wrote: > From: Bjorn Helgaas > > f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and ASPM states for devicetree > platforms") enabled Clock Power Management and L1 PM Substates, but those > features depend on CLKREQ# and possibly other device-specific > configuration. We don't know whether CLKREQ# is supported, so we shouldn't > blindly enable Clock PM and L1 PM Substates. > > Enable only ASPM L0s and L1, and only when both ends of the link advertise > support for them. > > Fixes: f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and ASPM states for devicetree platforms") > Reported-by: Christian Zigotzky > Link: https://lore.kernel.org/r/db5c95a1-cf3e-46f9-8045-a1b04908051a@xenosoft.de/ > Reported-by: FUKAUMI Naoki > Closes: https://lore.kernel.org/r/22594781424C5C98+22cb5d61-19b1-4353-9818-3bb2b311da0b@radxa.com/ > Reported-by: Herve Codina > Link: https://lore.kernel.org/r/20251015101304.3ec03e6b@bootlin.com/ > Reported-by: Diederik de Haas > Link: https://lore.kernel.org/r/DDJXHRIRGTW9.GYC2ULZ5WQAL@cknow-tech.com/ > Signed-off-by: Bjorn Helgaas > Tested-by: FUKAUMI Naoki Provisionally applied to pci/for-linus, hoping to make v6.18-rc3. Happy to add any testing reports or amend as needed. > --- > I intend this for v6.18-rc3. > > I think it will fix the issues reported by Diederik and FUKAUMI Naoki (both > on Rockchip). I hope it will fix Christian's report on powerpc, but don't > have confirmation. I think the performance regression Herve reported is > related, but this patch doesn't seem to fix it. > > FUKAUMI Naoki's successful testing report: > https://lore.kernel.org/r/4B275FBD7B747BE6+a3e5b367-9710-4b67-9d66-3ea34fc30866@radxa.com/ > --- > drivers/pci/pcie/aspm.c | 34 +++++++++------------------------- > 1 file changed, 9 insertions(+), 25 deletions(-) > > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > index 7cc8281e7011..79b965158473 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -243,8 +243,7 @@ struct pcie_link_state { > /* Clock PM state */ > u32 clkpm_capable:1; /* Clock PM capable? */ > u32 clkpm_enabled:1; /* Current Clock PM state */ > - u32 clkpm_default:1; /* Default Clock PM state by BIOS or > - override */ > + u32 clkpm_default:1; /* Default Clock PM state by BIOS */ > u32 clkpm_disable:1; /* Clock PM disabled */ > }; > > @@ -376,18 +375,6 @@ static void pcie_set_clkpm(struct pcie_link_state *link, int enable) > pcie_set_clkpm_nocheck(link, enable); > } > > -static void pcie_clkpm_override_default_link_state(struct pcie_link_state *link, > - int enabled) > -{ > - struct pci_dev *pdev = link->downstream; > - > - /* For devicetree platforms, enable ClockPM by default */ > - if (of_have_populated_dt() && !enabled) { > - link->clkpm_default = 1; > - pci_info(pdev, "ASPM: DT platform, enabling ClockPM\n"); > - } > -} > - > static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist) > { > int capable = 1, enabled = 1; > @@ -410,7 +397,6 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist) > } > link->clkpm_enabled = enabled; > link->clkpm_default = enabled; > - pcie_clkpm_override_default_link_state(link, enabled); > link->clkpm_capable = capable; > link->clkpm_disable = blacklist ? 1 : 0; > } > @@ -811,19 +797,17 @@ static void pcie_aspm_override_default_link_state(struct pcie_link_state *link) > struct pci_dev *pdev = link->downstream; > u32 override; > > - /* For devicetree platforms, enable all ASPM states by default */ > + /* For devicetree platforms, enable L0s and L1 by default */ > if (of_have_populated_dt()) { > - link->aspm_default = PCIE_LINK_STATE_ASPM_ALL; > + 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; > override = link->aspm_default & ~link->aspm_enabled; > if (override) > - pci_info(pdev, "ASPM: DT platform, enabling%s%s%s%s%s%s%s\n", > - FLAG(override, L0S_UP, " L0s-up"), > - FLAG(override, L0S_DW, " L0s-dw"), > - FLAG(override, L1, " L1"), > - FLAG(override, L1_1, " ASPM-L1.1"), > - FLAG(override, L1_2, " ASPM-L1.2"), > - FLAG(override, L1_1_PCIPM, " PCI-PM-L1.1"), > - FLAG(override, L1_2_PCIPM, " PCI-PM-L1.2")); > + pci_info(pdev, "ASPM: default states%s%s\n", > + FLAG(override, L0S, " L0s"), > + FLAG(override, L1, " L1")); > } > } > > -- > 2.43.0 >