From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: "Rafael J. Wysocki" To: Mika Westerberg Cc: Bjorn Helgaas , Bjorn Helgaas , Peter Wu , Lukas Wunner , linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, Valdis Kletnieks , Dave Airlie Subject: Re: [PATCH] PCI: Power on bridges before scanning new devices Date: Wed, 25 May 2016 02:03:06 +0200 Message-ID: <2974632.08s74OSxep@vostro.rjw.lan> In-Reply-To: <20160524211309.GH1789@lahna.fi.intel.com> References: <20160519231234.GB1785@al> <20160524125323.GE1789@lahna.fi.intel.com> <20160524211309.GH1789@lahna.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" List-ID: On Wednesday, May 25, 2016 12:13:09 AM Mika Westerberg wrote: > On Tue, May 24, 2016 at 03:53:23PM +0300, Mika Westerberg wrote: > > > I dropped "ACPI / hotplug / PCI: Runtime resume bridge before rescan" > > > on the assumption that "PCI: Power on bridges before scanning new > > > devices" is sufficient to cover both the ACPI and the generic PCi > > > rescan cases, but I'd like some reassurance about that. > > > > I agree with your reasoning that the patch should not be needed anymore. > > However, I have the machine which needed that patch at home so I'm not > > able to test it now. I'll do that later today when I get back home. > > I tried now on my Lenovo Yoga 900 laptop and unfortunately "PCI: Power > on bridges before scanning new devices" seems not to be enough. This > machine has SD-card reader connected to one PCIe port and once I unload > the sdhci-pci driver and enable runtime PM for the device, next system > suspend/resume cycle loses the SD-card reader PCI device. > > I will investigate more tomorrow -- it is getting late here. > > Anyway, maybe it is safer to postpone this series for v4.8 to give it > more testing time in -next. Agreed. I don't see a compelling enough reason to rush these changes into 4.7 and it looks like there are gaps in our understanding of the issues involved. Thanks, Rafael