From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 12 Sep 2016 17:07:10 -0500 From: Bjorn Helgaas To: Lukas Wunner Cc: linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , Peter Wu , Andreas Noever Subject: Re: [PATCH 0/4] PCI PM refinements Message-ID: <20160912220710.GH23532@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-ID: On Wed, Aug 31, 2016 at 08:15:18AM +0200, Lukas Wunner wrote: > The following patches are part of my Thunderbolt Runtime PM series. > I'm posting them separately to split the series into digestible chunks. > > They benefit everyone, not just Thunderbolt, and Thunderbolt works fine > without them (just not with the same degree of perfection). > > Patch [1/4] affords direct-complete to devices which are not platform- > power-manageable, yet can be suspended to D3cold with a nonstandard > mechanism. It does so using a heuristic: If a device's current_state > is D3cold and it is not power-manageable, it is assumed that a > nonstandard PM mechanism is at work and the device is left asleep. > The patch is the outcome of a discussion with Rafael and Alan on > linux-pci@ and I would like to thank both for tirelessly responding > to my questions. > > Patch [3/4] replaces the unconditional resume after direct-complete with > a conditional resume by determining if the platform firmware has put the > device in reset-power-on or not. > > Because the D3cold state cannot be determined from the PMCSR, patch [2/4] > adds a hook to query the platform firmware for its opinion on the device's > power state. > > Finally, patch [4/4] changes the shutdown handling of PCI devices such > that they are no longer woken without reason. > > The result of these patches should be a speedup and decreased power > consumption for system sleep and system shutdown (both for devices that > are platform-power-manageable and those that aren't). > > If you prefer point & click interfaces, the patches are browsable here: > https://github.com/l1k/linux/commits/thunderbolt_runpm_v3 Rafael, do you have any comment on these? I don't have any objections myself, but I'd like your opinion as the PM expert :) > Lukas Wunner (4): > PCI: Afford direct-complete to devices with nonstandard pm > PCI: Query platform firmware for device power state > PCI: Avoid unnecessary resume after direct-complete > PCI: Avoid unnecessary resume on shutdown > > drivers/pci/pci-acpi.c | 23 +++++++++++++++++++++++ > drivers/pci/pci-driver.c | 20 ++++++++++++++++++-- > drivers/pci/pci.c | 38 +++++++++++++++++++++++++++++++------- > drivers/pci/pci.h | 3 +++ > 4 files changed, 75 insertions(+), 9 deletions(-) > > -- > 2.8.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html