From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Tue, 3 Jan 2017 17:31:30 +0100 From: Peter Wu To: Lukas Wunner Cc: Mika Westerberg , "Rafael J. Wysocki" , Kilian Singer , Bjorn Helgaas , linux-pci , Alex Deucher , Dave Airlie Subject: Re: PCI: Revert "PCI: Add runtime PM support for PCIe ports" Message-ID: <20170103163130.GC9763@al> References: <20161228161816.GA19653@bhelgaas-glaptop.roam.corp.google.com> <20170102121019.GA3353@lahna.fi.intel.com> <20170102144852.GE3353@lahna.fi.intel.com> <1731082.izJCnRoq0n@aspire.rjw.lan> <20170103095158.GH3353@lahna.fi.intel.com> <20170103151547.GB9763@al> <20170103161123.GA20915@wunner.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170103161123.GA20915@wunner.de> List-ID: On Tue, Jan 03, 2017 at 05:11:23PM +0100, Lukas Wunner wrote: > [cc += Dave Airlie: > > Dave, we're about to lose support for newer Optimus laptops which use > _PR3 to cut power to the discrete GPU because Bjorn Helgaas has queued > a commit on his for-linus branch to remove runtime PM for PCIe ports. > This fixes a regression on Kilian Singer's laptop on which locking the > screen breaks USB and PS/2 input devices: Mouse movements are still > visible, but button or key presses no longer have any effect. The GPU > is powered down upon locking the screen and the current theory is that > this causes the issues.] (+cc Alex: this might affect amdgpu/radeon too.] Bjorn, please reconsider the rpm patch. Reverting support would introduce other regressions (see issues below) and make future Thunderbolt work harder (according to Lukas). If Kilian's laptop has issues, what about a "temporary" quirk? > On Tue, Jan 03, 2017 at 04:15:47PM +0100, Peter Wu wrote: > > The acpidump from the bug does not show known issues, it *looks* fine. > > There have been other issues related to resuming power on newer Nvidia > > hardware (https://bugs.freedesktop.org/show_bug.cgi?id=94725, > > https://bugzilla.kernel.org/show_bug.cgi?id=156341) but there is not > > much progress here. (The last time I traced the PCIe register accesses > > (via kprobes) and tried to disable some of those, it still did not help > > with preventing the power issue.) > > It seems that the _DSM method works on Kilian's laptop. Would it be > viable to default to _DSM if it's available, and only use _PR3 if not? DSM should not be preferred when PR3 is available: - After MS introduced D3cold (PR3) support to Win8+, vendors are unlikely to test legacy DSM and the likelihood of breakage increases. - On one Lenovo laptop, the DSM method causes memory corruption while PR3 fixes this problem. - On some laptops, DSM keeps the fan on while PR3 stopped the noise. - On some laptops, DSM does not really power off the GPU and results in increased power consumption during runtime/system sleep. PR3 fully removes the power, as desired. -- Kind regards, Peter Wu https://lekensteyn.nl