From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Oleksij Rempel (fishor)" Subject: Re: [PATCH] ACPI / PCI: Make _SxD/_SxW check follow ACPI 4.0a spec Date: Tue, 01 May 2012 18:27:17 +0200 Message-ID: <4FA00EE5.2060403@fisher-privat.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-pci-owner@vger.kernel.org To: Alan Stern Cc: "Rafael J. Wysocki" , Bjorn Helgaas , Len Brown , ACPI Devel Mailing List , Linux PM list , linux-pci@vger.kernel.org, LKML , Andrey Rahmatullin , Steven Rostedt List-Id: linux-acpi@vger.kernel.org On 01.05.2012 16:11, Alan Stern wrote: > On Tue, 1 May 2012, Rafael J. Wysocki wrote: > >>> I mean not just the mapping. >>> I mean PCI:PME_SUP field. If it PME(D0+,D1-,D2-,D3hot+,D3cold+), and >>> acpi trying to avoid D3 states for this device. then is is same like >>> PME(D0+,D1-,D2-)? Or not? >> >> Yes, if _S3D or _S3W are present. If they are not present and _PRW is, >> that means "don't care". >> >>> According to spec.: >>> 7.2 Device Power Management Objects (page 287) >>> _S3D - Highest D-state supported by the device in the S3 state >>> _S3W - Lowest D-state supported by the device in the S3 state which can >>> wake the system. >>> by definition if _S3W is specified then we can assume, the device can >>> wake? But _SxW is not defined. >> >> The device can wake up the system if _PRW is present for it (and for >> PCIe devices even that is not formally necessary). >> >>> Are there any other method to forbid the system use broken state, after >>> device was actually produced? Usual BIOS flash utility will probably no >>> rewrite the PCIs EEPROM. Only hope is ACPI, what is correct method to do >>> define it by ACPI? >> >> Define _S3D that will return 2 (for example) and _PRW returning 3 as the >> deepest sleep state the system may be woken up from. Then, we'll use >> D2 (after the @subject patch). >> >> The drawback is that the kernel will then think the device can wake up >> the system. > > There also remains a question about runtime power states and resume. > > Oleksij, with your patch, which state does the controller get put into > during runtime suspend, D2 or D3? (You may need to enable runtime > suspend by doing > > echo auto>/sys/bus/pci/devices/0000:00:1d.0/power/control > > in order to test this.) And if the controller is in runtime suspend, > does it resume correctly when you plug in a new USB device? > > I'm pretty sure that without the patch, the controller gets put into D3 > and resume does work. I do not know if device really suspended, but every thing works like before. New usb devices are recognized and working.