From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Message-ID: <1483974686.28993.3.camel@redhat.com> Subject: Re: PCI: Revert "PCI: Add runtime PM support for PCIe ports" From: Lyude Paul To: David Airlie , Peter Jones Cc: Lukas Wunner , "Rafael J. Wysocki" , Peter Wu , Bjorn Helgaas , Mika Westerberg , Kilian Singer , linux-pci , Alex Deucher , Hans de Goede , Lyude Date: Mon, 09 Jan 2017 10:11:26 -0500 In-Reply-To: <1931628154.8613274.1483644995907.JavaMail.zimbra@redhat.com> References: <20161228161816.GA19653@bhelgaas-glaptop.roam.corp.google.com> <20170104081639.GA21076@wunner.de> <20170104210954.GA11946@al> <59349185.1aqio7kYFn@aspire.rjw.lan> <1456065516.8360056.1483572074197.JavaMail.zimbra@redhat.com> <20170105150646.GB21446@wunner.de> <20170105181322.wnvdytpgddcdk3ry@redhat.com> <1931628154.8613274.1483644995907.JavaMail.zimbra@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-ID: fwiw, I just tried on the W541 I have 4.8.15-300.fc25.x86_64 running on here and so far it seems to suspend/resume just fine using firmware version 2.19 On Thu, 2017-01-05 at 14:36 -0500, David Airlie wrote: > (cc'ing Lyude, who has the hw also I think). > > ----- Original Message ----- > > From: "Peter Jones" > > To: "Lukas Wunner" > > Cc: "David Airlie" , "Rafael J. Wysocki" > jwysocki.net>, "Peter Wu" , > > "Bjorn Helgaas" , "Mika Westerberg" > rberg@linux.intel.com>, "Kilian Singer" > > , "linux-pci" > .kernel.org>, "Alex Deucher" > > , "Hans de Goede" > > Sent: Friday, 6 January, 2017 4:13:23 AM > > Subject: Re: PCI: Revert "PCI: Add runtime PM support for PCIe > > ports" > > > > On Thu, Jan 05, 2017 at 04:06:46PM +0100, Lukas Wunner wrote: > > > On Wed, Jan 04, 2017 at 06:21:14PM -0500, David Airlie wrote: > > > > > On Wednesday, January 04, 2017 10:09:54 PM Peter Wu wrote: > > > > > > On Wed, Jan 04, 2017 at 09:16:39AM +0100, Lukas Wunner > > > > > > wrote: > > > > > > > On Tue, Jan 03, 2017 at 06:05:57PM -0600, Bjorn Helgaas > > > > > > > wrote: > > > > > > > > I don't *want* to apply the revert.  It's on my for- > > > > > > > > linus branch > > > > > > > > as a > > > > > > > > worst-case scenario change if we can't figure out a > > > > > > > > better fix. > > > > > > > > > > > > > > > > The patch below is preferable, but I'd rather not take > > > > > > > > even it, > > > > > > > > because it takes away functionality and forces people > > > > > > > > to use a > > > > > > > > boot > > > > > > > > parameter to restore it.  I expect that somebody will > > > > > > > > figure out > > > > > > > > how > > > > > > > > to fix the regression Kilian found and also keep the > > > > > > > > new > > > > > > > > functionality > > > > > > > > (without requiring boot parameters) before v4.10. > > > > > > > > > > > > > > The issue is constrained to hybrid graphics laptops with > > > > > > > Nvidia > > > > > > > discrete > > > > > > > GPU using nouveau.  Hence it needs to be fixed in > > > > > > > nouveau, not in > > > > > > > the > > > > > > > PCI core. > > > > > > > > > > > > The problem is not necessarily in the nouveau driver, the > > > > > > same > > > > > > problem > > > > > > occurs when you enable RPM without loading nouveau. The > > > > > > issue is > > > > > > limited > > > > > > though to some newer hybrid graphics laptops with Nvidia > > > > > > GPUs. While > > > > > > a > > > > > > quirk can be added to nouveau, I think that a (temporary) > > > > > > quirk in > > > > > > core > > > > > > would also be reasonable (since it also occurs without > > > > > > nouveau). > > > > > > > > > > > > > (AFAIUI, laptops with AMD discrete GPU are not affected > > > > > > > as it is > > > > > > > known > > > > > > > when and how to call an ACPI method versus using PR3.) > > > > > > > > > > > > > > (Neither are laptops using the Nvidia proprietary driver > > > > > > > as it > > > > > > > doesn't > > > > > > > runtime suspend the card.  But battery life will be > > > > > > > terrible then.) > > > > > > > > > > > > > > We're at rc2 so the time frame for coming up with a fix > > > > > > > is probably > > > > > > > 4 weeks.  Peter and others have tried for months to > > > > > > > reverse-engineer > > > > > > > how to handle runtime PM on newer Nvidia cards.  It seems > > > > > > > likely > > > > > > > that > > > > > > > we'll not find the ultimate solution to the problem > > > > > > > within 4 weeks. > > > > > > > > > > > > Yep, a quick proper fix seems unlikely. > > > > > > [ Help/ideas are welcome, I suspect that these failures to > > > > > > restore > > > > > > power > > > > > > on laptops designed for Win8+ all have the same cause, > > > > > > related to > > > > > > some > > > > > > unknown interaction between ACPI and PCI. Some links: > > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=190861 > > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=156341 ] > > > > > > > > > > > > > The way it is now, i.e. defaulting to PR3 when available, > > > > > > > regresses > > > > > > > certain laptops such as Kilian's.  If on the other hand > > > > > > > we default > > > > > > > to > > > > > > > DSM when available, we'll regress certain other laptops, > > > > > > > as Peter > > > > > > > has > > > > > > > pointed out.  Whitelisting or blacklisting laptops > > > > > > > doesn't seem a > > > > > > > good > > > > > > > approach either, ideally we'd want to use PR3 as Windows > > > > > > > does. > > > > > > > > > > > > > > As said, the only short-term solution I see is to add an > > > > > > > "optimus" > > > > > > > module_param to nouveau to allow users to select which > > > > > > > method to > > > > > > > use. > > > > > > > So in Kilian's case an additional command line parameter > > > > > > > would be > > > > > > > necessary to fix the issue. > > > > > > > > > > > > > > Does anyone see a better solution or can we agree on this > > > > > > > one?  If > > > > > > > so > > > > > > > I can come up with a patch.  This could go in via Dave > > > > > > > Airlie's > > > > > > > tree. > > > > > > > > > > > > As pcie_port_pm=off already reverts to DSM, I do not think > > > > > > that an > > > > > > additional (temporary) nouveau module parameter is going to > > > > > > help. I > > > > > > instead propose a (hopefully temporary) quirk in pci core > > > > > > that > > > > > > disables > > > > > > D3cold RPM for just Kilians Lenovo laptop (basically > > > > > > defaulting to > > > > > > pcie_port_pm=off). Then the option pcie_port_pm=force can > > > > > > still be > > > > > > used > > > > > > to test possible solutions in the future. > > > > > > > > > > I would rather add a quirk to the ACPI core to prevent the > > > > > power > > > > > resources in > > > > > question from being enumerated.  Or even to prevent ACPI PM > > > > > from being > > > > > used for the port in question. > > > > > > > > I do have a W541 in a cupboard in the office somewhere, but I > > > > won't be > > > > close to > > > > it for a couple of weeks. The W541 was the first place I tested > > > > the pm > > > > patches > > > > so I'm kinda wondering whether it's all W541's or just some > > > > specific > > > > model/bios > > > > combo. > > > > They seem to all ship with the 1.10 firmware, and 2.80 is current > > (there > > are a bunch of intermediate 2.xx versions).  Somewhere along the > > line > > they introduced some bugs in the UEFI stuff, so it wouldn't be > > surprising if there's bugs introduced elsewhere as well. > > > > > > However I'm pretty much unavailable to do anything much until > > > > late Jan on > > > > this. > > > > > > Is there anyone else at Red Hat who might be able to look into > > > this? > > > > > > ISTR that Hans de Goede is working on improving laptop support in > > > Fedora, > > > and Peter Jones recently got a patch merged for the W541 with the > > > exact > > > same firmware Kilian is using to work around a botched EFI memory > > > map. > > > Adding them to cc: in the hope that they may be able to help. > > > > > > @Peter, have you noticed issues with the discrete Nvidia GPU on > > > your W541 > > > related to runtime suspend and system sleep? > > > > I was using a borrowed one (I can certainly find it again, but I'm > > not > > working on graphics/pm really), but yeah - shutdown and lspci both > > broke > > sometime after pci_pm_runtime_resume().  Here's the traceback from > > SYS_reboot(): https://goo.gl/photos/T1fr1bksHQb9RSU67 > > > > Dave, if you know who in Westford should have a look at this, I can > > see > > about getting them hardware.  I am more or less surrounded by that > > team. > > > > -- > >         Peter > >