Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752002AbdFSRpi (ORCPT ); Mon, 19 Jun 2017 13:45:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:42078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751919AbdFSRpg (ORCPT ); Mon, 19 Jun 2017 13:45:36 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 616F4239B8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Mon, 19 Jun 2017 12:45:33 -0500 From: Bjorn Helgaas To: Kai-Heng Feng Cc: Alan Stern , Bjorn Helgaas , gregkh@linuxfoundation.org, USB list , linux-pci@vger.kernel.org, LKML , "Rafael J. Wysocki" , linux-pm@vger.kernel.org Subject: Re: [PATCH] usb: host: ehci: workaround PME bug on AMD EHCI controller Message-ID: <20170619174533.GA20550@bhelgaas-glaptop.roam.corp.google.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1793 Lines: 41 On Mon, Jun 19, 2017 at 11:30:18AM +0800, Kai-Heng Feng wrote: > On Sat, Jun 17, 2017 at 1:30 AM, Alan Stern wrote: > > On Sat, 17 Jun 2017, Kai-Heng Feng wrote: > > > >> On Fri, Jun 16, 2017 at 11:07 AM, Kai-Heng Feng > >> wrote: > >> > On Thu, Jun 15, 2017 at 10:12 PM, Alan Stern wrote: > >> >> Those documents refer to a hardware bug with a workaround in the BIOS. > >> >> Have you checked to see if your BIOS is up to date? > >> > > >> > Yes, it's up to date. > >> > > >> > >> Alan, I re-sent a patch but I forgot to add you to CC list: > >> http://marc.info/?l=linux-pci&m=149760607914628&w=2 > > > > Thanks for letting me know. The patch seems reasonable. > > > > Have you tested it with system suspend? That is, if you suspend the > > whole computer, does plugging or unplugging a USB device cause the > > system to wake up? > > No, the system will not wake up when plugging or unplugging. > Tried several times, nether runtime PM enabled nor runtime PM disabled > will wake up the system under S3, when (un)plugging USB devices. Alan, I don't know what this test means for the patch (http://marc.info/?l=linux-pci&m=149760607914628&w=2). pci_target_state() is documented as "return the deepest state from which the device can generate wake events." For this device, I guess that means D2, and the patch should accomplish that. I don't know what's supposed to happen to this device when the system is in S3. I assume that if the system is in S3, most devices are in D3. If this device is in D3, we won't get PMEs, which I guess is what Kai-Heng is seeing. Is that the desired behavior? Or do we want the PMEs enough that we should leave the device in D2 (if that's even possible)? Bjorn