Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756399Ab3D1SzS (ORCPT ); Sun, 28 Apr 2013 14:55:18 -0400 Received: from netrider.rowland.org ([192.131.102.5]:44592 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751707Ab3D1SzQ (ORCPT ); Sun, 28 Apr 2013 14:55:16 -0400 Date: Sun, 28 Apr 2013 14:55:14 -0400 (EDT) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: ZhenHua cc: gregkh@linuxfoundation.org, , Subject: Re: [PATCH 1/1] driver,usb: Fix a warning in uhci-hcd driver In-Reply-To: <517C808A.2060502@hp.com> Message-ID: MIME-Version: 1.0 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: 2895 Lines: 70 On Sun, 28 Apr 2013, ZhenHua wrote: > >>> In fact, the patch is so easy that I am including it below. Please > >>> test this (without either of your patches) to see if it works. > >>> > >>> Alan Stern > >>> > >>> > >>> > >>> > >>> Index: usb-3.9/drivers/usb/host/uhci-hub.c > >>> =================================================================== > >>> --- usb-3.9.orig/drivers/usb/host/uhci-hub.c > >>> +++ usb-3.9/drivers/usb/host/uhci-hub.c > >>> @@ -225,7 +225,8 @@ static int uhci_hub_status_data(struct u > >>> /* auto-stop if nothing connected for 1 second */ > >>> if (any_ports_active(uhci)) > >>> uhci->rh_state = UHCI_RH_RUNNING; > >>> - else if (time_after_eq(jiffies, uhci->auto_stop_time)) > >>> + else if (time_after_eq(jiffies, uhci->auto_stop_time) && > >>> + !uhci->wait_for_hp) > >>> suspend_rh(uhci, UHCI_RH_AUTO_STOPPED); > >>> break; > >>> > >>> > >> I have tested the UHCI_RH_RUNNING_NODEVS case yeasterday, and it works. > >> But the function suspend_rh is also called in other places, so I think > >> it only fixes > >> the warning when auto stop is called, but not fix the warning when > >> uhci's bus_suspend > >> is called, it will come out again. > > Have you tried this? I expect the warning will not occur when the > > bus_suspend routine is called, because then there will be a 1-ms delay, > > not just a 400-us delay. > I tested this, and the warning is gone. Is this patch committed ? > I need to paste the link to suse bugzilla. You must be joking. I wrote that patch while composing the email message to you, and nobody except you has tested it. Since you confirm that it works, I will submit it. But new patches like this won't be accepted until after the upcoming merge window closes, which won't be for more than two weeks. > >> And if you add uhci->wait_for_hp check in the UHCI_RH_RUNNING_NODEVS case, > >> all hp uhci devices will not auto stop, not only the virtual devices. I > >> guess it may waste resource. > > If you want, you can add a new flag specifically for virtual > > controllers. But it shouldn't matter -- as long as your kernels are > > built with CONFIG_PM_RUNTIME enabled, there won't be any significant > > waste of resources. > > > > Alan Stern > > > I think we can check the product id to determine whether a device is > virtual. > Do you know if there is another way to check this? I don't know anything at all about your virtual UHCI controllers, other than what you have told me. In particular, I don't know what product IDs are used by HP's virtual and non-virtual controllers. Maybe somebody else at HP can tell you. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/