From: Bjorn Helgaas <helgaas@kernel.org>
To: "Kenneth R. Crudup" <kenny@panix.com>
Cc: Vidya Sagar <vidyas@nvidia.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Commit 4257f7e0 ("PCI/ASPM: Save/restore L1SS Capability for suspend/resume") causing hibernate resume failures
Date: Wed, 27 Jan 2021 09:50:23 -0600 [thread overview]
Message-ID: <20210127155023.GA2988674@bjorn-Precision-5520> (raw)
In-Reply-To: <2563ba4a-81bc-d27-2670-cae48690db5e@panix.com>
On Fri, Jan 22, 2021 at 12:11:08PM -0800, Kenneth R. Crudup wrote:
> > > From: Kenneth R. Crudup <kenny@panix.com>
> > > I've been running Linus' master branch on my laptop (Dell XPS 13
> > > 2-in-1). With this commit in place, after resuming from hibernate
> > > my machine is essentially useless, with a torrent of disk I/O errors
> > > on my NVMe device (at least, and possibly other devices affected)
> > > until a reboot.
> > >
> > > I do use tlp to set the PCIe ASPM to "performance" on AC and
> > > "powersupersave" on battery.
>
> On Sun, 27 Dec 2020, Bjorn Helgaas wrote:
>
> > Thanks a lot for the report, and sorry for the breakage.
> > 4257f7e008ea restores PCI_L1SS_CTL1, then PCI_L1SS_CTL2. I think it
> > should do those in the reverse order, since the Enable bits are in
> > PCI_L1SS_CTL1. It also restores L1SS state (potentially enabling
> > L1.x) before we restore the PCIe Capability (potentially enabling ASPM
> > as a whole). Those probably should also be in the other order.
>
> Any new news on this? Disabling "tlp" (which just shifts the problem around
> on my machine) shouldn't be a solution for this issue.
Agreed; disabling "tlp" is a workaround but not a solution.
> I'd thought it may have been tied to some of the PM regressions of the last
> week of December, but all of those have been fixed but this still remains.
I haven't seen anything yet and haven't had a chance to look into it
more myself.
We're at v5.11-rc5 already, so I guess we'll have to think about
reverting 4257f7e008ea ("PCI/ASPM: Save/restore L1SS Capability for
suspend/resume") before v5.11-final unless we can make some progress.
That would mean ASPM L1 substate configuration would be lost by a
suspend/resume, so we'd give up some power saving. But that's better
than the regression you're seeing.
I'll tentatively queue up a revert on for-linus pending progress on a
better fix. For some reason I can't find your initial report of the
regression. The first thing I can find is this:
https://lore.kernel.org/linux-pci/20201228040513.GA611645@bjorn-Precision-5520/
Do you have a URL for your initial report that I could include in the
revert commit log?
Bjorn
next prev parent reply other threads:[~2021-01-27 15:51 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-28 4:05 Commit 4257f7e0 ("PCI/ASPM: Save/restore L1SS Capability for suspend/resume") causing hibernate resume failures Bjorn Helgaas
2020-12-28 4:41 ` Kenneth R. Crudup
2020-12-28 5:43 ` Kenneth R. Crudup
2020-12-28 6:30 ` Kenneth R. Crudup
2020-12-30 6:55 ` Vidya Sagar
2021-01-22 20:11 ` Kenneth R. Crudup
2021-01-27 15:50 ` Bjorn Helgaas [this message]
2021-01-27 16:00 ` Kenneth R. Crudup
2021-01-27 16:03 ` Kenneth R. Crudup
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