From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5889D395AD1; Fri, 16 Oct 2026 05:38:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792129124; cv=none; b=Uv3G7rUfzfuWH1woy0GdFS8ucYoC35ltE7yii9B/mgCa/eiIDN1gc6pJAYfKcgZu51UtfsVo+nBIOrOv6eynZgJHWB/wZOReVVmqeCqB5VetPl4w5cI+B/21IiQK9lci1nbDOIIW87dM+qSXMXFWZNtUyxsw1FceTRs9sK2XVLQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792129124; c=relaxed/simple; bh=yRN3IHAhSLlcnOHRWDVjO0jp4mGUUNVEuWi+SGMy2w4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iOk2wM8d92q9NM6lHIYsVD4n9K0vcMmsFooUvS4fwLdbUt7PqaFDXURET/jrb9kcjIii7hHv8fi23ZWIJ1HVI2LRyqaB9TgF0/Dq4BlCmkqKteNDLYpORp798fwbU23ZUKj4GYEl2eGtNYcnhE1cFeD+VazAxvz4egKkl2c+hFQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TGISrgXL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TGISrgXL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B45551F000C4; Fri, 16 Oct 2026 05:38:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792129122; bh=ktqFSsAx52niNcMbY6VRLuj3WY+yJAl8EZhfxOg24+s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=TGISrgXLsZT/CTjeLsAIaY1W0qIJ+pKBQSG0YeThNt4I/0JCvBaoFTZAPXWGmHCad FsWo1l2SSLWIKzSvLrhQpv5RbEyMiS+3pLkdKeUqdI9Uk4YLk/L/vJ2HvpJaGqnDDO +xukVVIwCLfi9Vf2MFtSwhWzIhF20wpuJ+19jo3+tYu6fOGJZ1jb3P3d7137vUmDcE VXwdaCVqJW2wbuIlM5oNG8z7Xoa2OlFQ1P8YDaXGTBofxnC5/nd93f02C2zlRsXGwa Es0sLy0Tre9LPf3lT0Es5b2CEG0RwsvGfI7IcwB7oqKiYzEIxG7NnvW+SDXs2+7s7s tytdwblQwdoDA== Date: Fri, 16 Oct 2026 11:08:29 +0530 From: Manivannan Sadhasivam To: Bjorn Helgaas Cc: Bjorn Helgaas , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Nirmal Patel , Jonathan Derrick , Jeff Johnson , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-wireless@vger.kernel.org, ath12k@lists.infradead.org, ath11k@lists.infradead.org, ath10k@lists.infradead.org, Krishna Chaitanya Chundru , Qiang Yu , Ilpo =?utf-8?B?SsOkcnZpbmVu?= Subject: Re: [PATCH v3 1/8] PCI/ASPM: Always disable ASPM when driver requests it Message-ID: References: <20260708-pci-aspm-fix-v3-1-6bd72451746e@kernel.org> <20261015230714.GA1802070@bhelgaas> Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20261015230714.GA1802070@bhelgaas> On Thu, Oct 15, 2026 at 06:07:14PM -0500, Bjorn Helgaas wrote: > On Wed, Jul 08, 2026 at 04:30:15PM +0200, Manivannan Sadhasivam wrote: > > From: Ilpo Järvinen > > > > PCI core/ASPM service driver allows controlling ASPM state through > > pci_disable_link_state() API. It was decided earlier (see the Link > > below), to not allow ASPM changes when OS does not have control over it > > but only log a warning about the problem 'commit 2add0ec14c25 ("PCI/ASPM: > > Warn when driver asks to disable ASPM, but we can't do it")'. > > > > A number of drivers have added workarounds to force ASPM off with own > > writes into the Link Control Register (some even with comments > > explaining why PCI core does not disable it under some circumstances). > > According to the comments, some drivers require ASPM to be off for > > reliable operation. > > > > Having custom ASPM handling in drivers is problematic because the state > > kept in the ASPM service driver is not updated by the changes made > > outside the link state management API. > > > > As the first step to address this issue, make pci_disable_link_state() > > to unconditionally disable ASPM so the motivation for drivers to come > > up with custom ASPM handling code is eliminated. > > > > To fully take advantage of the ASPM handling core provides, the drivers > > that need to quirk ASPM have to be altered depend on PCIEASPM and the > > custom ASPM code is removed. This is to be done separately. As PCIEASPM > > is already behind EXPERT, it should be no problem to limit disabling it > > for configurations that do not require touching ASPM. > > > > Make pci_disable_link_state() function comment to comply kerneldoc > > formatting while changing the description. > > > > Link: https://lore.kernel.org/all/CANUX_P3F5YhbZX3WGU-j1AGpbXb_T9Bis2ErhvKkFMtDvzatVQ@mail.gmail.com/ > > Link: https://lore.kernel.org/all/20230511131441.45704-1-ilpo.jarvinen@linux.intel.com/ > > Signed-off-by: Ilpo Järvinen > > [mani: commit message fixup] > > Signed-off-by: Manivannan Sadhasivam > > I was a little confused about the provenance of this patch. It > *looks* like it should have been posted somewhere by Ilpo and > something tweaked by Mani when applying, but none of the links above > are a posting of this patch. I dug around and found > https://lore.kernel.org/linux-pci/20230918131103.24119-4-ilpo.jarvinen@linux.intel.com/, > and this patch looks like basically the aspm.c part of it, so I assume > that should probably be the https://patch.msgid.link/? > Ilpo shared this patch during the review of v1 of this series: https://lore.kernel.org/linux-pci/52baf40b-41ed-2588-7817-4d8cd859e0d1@linux.intel.com/ > To fix the provenance and the "Drivers can controlling" typo mentioned > by Ilpo, I replaced this with just the aspm.c changes from > https://lore.kernel.org/linux-pci/20230918131103.24119-4-ilpo.jarvinen@linux.intel.com/ > and added the CONFIG_PCIEASPM dependency to the commit log. The code > change is the same. > This looks good to me. - Mani -- மணிவண்ணன் சதாசிவம்