From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 934B226281; Tue, 15 Jul 2025 14:50:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.3 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752591016; cv=none; b=aw/iAHP1H1BV0F09AQp9oo4Hsuqa/nhVEyJbj87EDNrMctfav92leBqTeQCvnOFxVH7TTRsMw+G3p9ajoBaN5SxYZ0beWAUBN1+GU+a05G8UNpBTYVskFvz6uBYQG0UkzdI+/qFQxMzdnf6yzjM/rjbyyXEPH90SH3b8NiqiDzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752591016; c=relaxed/simple; bh=KwW3Ct+eYQAN7duoTjUPdigF52dVr0dEmIwj3cGLFWI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ol+1ug0scDXCAtjDsV80zQTkOU/ZJgY/mvMYAD+ZKlOA1f6+fxe7LiZ3qPGNLxqNmpYreKJd9fBhPrVyNLgnTNoJwoVGygUhK1GWb0zjm/YO7s12Wb1inNgkXA07IPNcKlIdHrO5u1dCChOux3IL0YEv3NkV45euklQykSmSItI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=DV3FuCcu; arc=none smtp.client-ip=220.197.31.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="DV3FuCcu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:To:From: Content-Type; bh=y8FmBktC9WSRYxvxolkGYL5S4AI0gxd1QPXCyRbb+Bw=; b=DV3FuCcum96CB6OJl3oa/EcvfiVGdVsWmvSySDMjIyTZCnpMC4bboVdDK+mD72 GtTSSKWuSnsg+whFjBRn8GL29NJh9i/eTQ4cD8j1VMxO6p5BvyrgKhq8LkBu0ksv MNbGlbHEC2XQO11n4cIfhSj3hQLoS3vZBSMdzm35evdjk= Received: from [IPV6:240e:b8f:919b:3100:7981:39b4:a847:709a] (unknown []) by gzga-smtp-mtada-g1-2 (Coremail) with SMTP id _____wAH7fhVanZoxSGjFA--.45568S2; Tue, 15 Jul 2025 22:48:54 +0800 (CST) Message-ID: <7da900a6-04cd-41f7-afc8-5570eb7639e1@163.com> Date: Tue, 15 Jul 2025 22:48:53 +0800 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 06/11] PCI/ASPM: Clear aspm_disable as part of __pci_enable_link_state() To: Bjorn Helgaas Cc: Manivannan Sadhasivam , =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= , Krishna Chaitanya Chundru , Bjorn Helgaas , Jingoo Han , Lorenzo Pieralisi , Rob Herring , Jeff Johnson , Bartosz Golaszewski , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , linux-pci@vger.kernel.org, LKML , linux-arm-msm@vger.kernel.org, mhi@lists.linux.dev, linux-wireless@vger.kernel.org, ath11k@lists.infradead.org, qiang.yu@oss.qualcomm.com, quic_vbadigan@quicinc.com, quic_vpernami@quicinc.com, quic_mrana@quicinc.com, Jeff Johnson References: <20250714193214.GA2415073@bhelgaas> Content-Language: en-US From: Hans Zhang <18255117159@163.com> In-Reply-To: <20250714193214.GA2415073@bhelgaas> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID:_____wAH7fhVanZoxSGjFA--.45568S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxJFW7tw18Gry7Cr1DXFW5ZFb_yoW5Xr1xpa yrtasIkFZ5Jr97Gw12vw1jqF4SkwnYy345G3s5tryUJw45u39xGr4xtrZY9F93WrWxW3ya vrZ8WwnrZFyq9a7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07URa0QUUUUU= X-CM-SenderInfo: rpryjkyvrrlimvzbiqqrwthudrp/1tbiQwWLo2h2Y3mQSAAAsy On 2025/7/15 03:32, Bjorn Helgaas wrote: > On Sun, Jul 13, 2025 at 12:05:18AM +0800, Hans Zhang wrote: >> On 2025/7/12 17:35, Manivannan Sadhasivam wrote: >> ... > >>>> IMO the "someday" goal should be that we get rid of aspm_policy >>>> and enable all the available power saving states by default. We >>>> have sysfs knobs that administrators can use if necessary, and >>>> drivers or quirks can disable states if they need to work around >>>> hardware defects. >>> >>> Yeah, I think the default should be powersave and let the users >>> disable it for performance if they want. >> >> Perhaps I don't think so. At present, our company's testing team has >> tested quite a few NVMe SSDS. As far as I can remember, the SSDS >> from two companies have encountered problems and will hang directly >> when turned on. We have set CONFIG_PCIEASPM_POWERSAVE=y by default. >> When encountering SSDS from these two companies, we had to add >> "pcie_aspm.policy=default" in the cmdline, and then the boot worked >> normally. Currently, we do not have a PCIe protocol analyzer to >> analyze such issues. The current approach is to modify the cmdline. >> So I can't prove whether it's a problem with the Root Port of our >> SOC or the SSD device. > > Have you reported these? Dear Bjorn, I haven't reported it. Because we don't have a PCIe protocol analyzer to analyze this situation, it's not certain whether it's a problem with our SOC Root Port or the NVMe SSD. If I have time later, I will conduct a comparison test on the RK3588. > >> Here I agree with Bjorn's statement that sometimes the EP is not >> necessarily very standard and there are no hardware issues. >> Personally, I think the default is default or performance. When >> users need to save power, they should then decide whether to >> configure it as powersave or powersupersave. Sometimes, if the EP >> device connected by the customer is perfect, they can turn it on to >> save power. But if the EP is not perfect, at least they will >> immediately know what caused the problem. > > We should discover device defects as early as possible so we can add > quirks for them. Defaulting to ASPM being partly disabled means it > gets much less testing and users end up passing around "fixes" like > booting with "pcie_aspm.policy=default" or similar. I do not want > users to trip over a device that doesn't work and have to look for > workarounds on the web. > > I also think it's somewhat irresponsible of us to consume more power > than necessary. But as Mani said, this would be a big change and > might have to be done with a BIOS date check or something to try to > avoid regressions. > Ok. I understand your purpose now. Best regards, Hans