Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753249AbdGYUnk (ORCPT ); Tue, 25 Jul 2017 16:43:40 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:53401 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752681AbdGYUnh (ORCPT ); Tue, 25 Jul 2017 16:43:37 -0400 From: "Rafael J. Wysocki" To: Alan Stern Cc: Linux USB , Linux PM , LKML , Greg Kroah-Hartman , Mathias Nyman , Felipe Balbi Subject: Re: [PATCH] PM / USB: hcd_pci: Skip secondary root hub check for HCD_DEAD() Date: Tue, 25 Jul 2017 22:35:37 +0200 Message-ID: <1934081.cLRahvktBu@aspire.rjw.lan> User-Agent: KMail/4.14.10 (Linux/4.12.0-rc1+; KDE/4.14.9; x86_64; ; ) In-Reply-To: <2055160.bTgMse1pkO@aspire.rjw.lan> References: <2055160.bTgMse1pkO@aspire.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2186 Lines: 61 On Tuesday, July 25, 2017 05:59:04 PM Rafael J. Wysocki wrote: > On Tuesday, July 25, 2017 10:05:03 AM Alan Stern wrote: > > On Tue, 25 Jul 2017, Rafael J. Wysocki wrote: > > > > > From: Rafael J. Wysocki > > > > > > If HCD_DEAD(hcd) is "true" in check_root_hub_suspended(), it is > > > rather pointless to check the secondary root hub, so return early > > > then. > > > > > > This actually fixes occasional suspend failures on one of my test > > > machines. > > > > > > Signed-off-by: Rafael J. Wysocki > > > --- > > > drivers/usb/core/hcd-pci.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > Index: linux-pm/drivers/usb/core/hcd-pci.c > > > =================================================================== > > > --- linux-pm.orig/drivers/usb/core/hcd-pci.c > > > +++ linux-pm/drivers/usb/core/hcd-pci.c > > > @@ -427,6 +427,9 @@ static int check_root_hub_suspended(stru > > > dev_warn(dev, "Root hub is not suspended\n"); > > > return -EBUSY; > > > } > > > + if (HCD_DEAD(hcd)) > > > + return 0; > > > + > > > if (hcd->shared_hcd) { > > > hcd = hcd->shared_hcd; > > > if (HCD_RH_RUNNING(hcd)) { > > > > While this is an okay solution, IMO it would be more reliable and more > > general to have usb_hc_died() clear the HCD_FLAG_RH_RUNNING bit and set > > the HCD_FLAG_DEAD bit in the shared hcd. Right now it only does these > > things for the primary. > > > > Would you like to write and test a patch to do that? > > I can do that. Just to make sure that we are on the same page, is the below what you mean? --- drivers/usb/core/hcd.c | 2 ++ 1 file changed, 2 insertions(+) Index: linux-pm/drivers/usb/core/hcd.c =================================================================== --- linux-pm.orig/drivers/usb/core/hcd.c +++ linux-pm/drivers/usb/core/hcd.c @@ -2485,6 +2485,8 @@ void usb_hc_died (struct usb_hcd *hcd) } if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) { hcd = hcd->shared_hcd; + clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags); + set_bit(HCD_FLAG_DEAD, &hcd->flags); if (hcd->rh_registered) { clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);