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Subject: Re: Lost PCIe PME after a914ff2d78ce ("PCI/ASPM: Don't select
 CONFIG_PCIEASPM by default")
To:     Matthew Garrett <mjg59@srcf.ucam.org>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>
Cc:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org
References: <bdc33be8-1db6-b147-cbc4-90fa0dc3d999@gmail.com>
 <20200529202135.GA461617@bjorn-Precision-5520>
 <20200529205900.whx3mxuvt6ijlqwg@srcf.ucam.org>
 <824d63d8-668c-22c8-a303-b44e30e805e1@gmail.com>
 <20200529225801.szl4obsas6ndilz4@srcf.ucam.org>
From:   Heiner Kallweit <hkallweit1@gmail.com>
Message-ID: <7c8cab08-e2d4-1952-1923-aa023ea67657@gmail.com>
Date:   Sat, 30 May 2020 08:33:50 +0200
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On 30.05.2020 00:58, Matthew Garrett wrote:
> On Sat, May 30, 2020 at 12:26:17AM +0200, Heiner Kallweit wrote:
>  
>> Current situation means that PME is unusable on all systems where
>> pcie_aspm_support_enabled() returns false, what is basically every
>> system except EXPERT mode is enabled and CONFIG_PCIEASPM is set.
>> So we definitely need to do something.
> 
> CONFIG_PCIEASPM is default y. I don't think there's huge value in 
> adding complexity to deal with it being disabled, given that the kernel 
> is then in a configuration that no vendor is testing against. There are 
> existing runtime mechanisms to disable it at runtime.
>  
> 
It *was* default y. This changed with a914ff2d78ce ("PCI/ASPM: Don't
select CONFIG_PCIEASPM by default") and that's what triggered the
problem. If there's no easy solution, then maybe it's best to revert
the change for now.