From patchwork Thu Dec 13 20:08:57 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 206209 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 6954F2C0094 for ; Fri, 14 Dec 2012 07:08:45 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756624Ab2LMUIY (ORCPT ); Thu, 13 Dec 2012 15:08:24 -0500 Received: from mga11.intel.com ([192.55.52.93]:58537 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756343Ab2LMUIV (ORCPT ); Thu, 13 Dec 2012 15:08:21 -0500 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP; 13 Dec 2012 12:08:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,275,1355126400"; d="asc'?scan'208";a="261824786" Received: from blue.fi.intel.com ([10.237.72.156]) by fmsmga001.fm.intel.com with ESMTP; 13 Dec 2012 12:08:17 -0800 Received: by blue.fi.intel.com (Postfix, from userid 1000) id 72FE6E0073; Thu, 13 Dec 2012 22:08:57 +0200 (EET) Date: Thu, 13 Dec 2012 22:08:57 +0200 From: "Kirill A. Shutemov" To: Greg KH Cc: Miles J Penner , John Ronciak , Mika Westerberg , Tushar N Dave , "Kirill A. Shutemov" , Bjorn Helgaas , Yinghai Lu , Jesse Barnes , Amos Kong , "Rafael J. Wysocki" , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] PCI Hotplug: workaround for Thunderbolt on Intel DZ77RE-75K motherboard Message-ID: <20121213200857.GA24939@otc-wbsnb-06> References: <1355412708-20046-1-git-send-email-kirill.shutemov@linux.intel.com> <1355412708-20046-4-git-send-email-kirill.shutemov@linux.intel.com> <20121213184820.GC12105@kroah.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20121213184820.GC12105@kroah.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Dec 13, 2012 at 10:48:20AM -0800, Greg KH wrote: > On Thu, Dec 13, 2012 at 05:31:48PM +0200, Kirill A. Shutemov wrote: > > From: "Kirill A. Shutemov" > > > > BIOS on Intel DZ77RE-75K motherboard notifies OS about Thunderbolt > > hotplug before devices behind Thunderbolt are ready to be enumerated. > > > > Let's delay enumeration by 2 seconds. > > > > Signed-off-by: Kirill A. Shutemov > > --- > > drivers/pci/hotplug/acpiphp_glue.c | 16 +++++++++++++++- > > 1 file changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > > index 1a2b3ca..165987a 100644 > > --- a/drivers/pci/hotplug/acpiphp_glue.c > > +++ b/drivers/pci/hotplug/acpiphp_glue.c > > @@ -49,6 +49,7 @@ > > #include > > #include > > #include > > +#include > > > > #include "../pci.h" > > #include "acpiphp.h" > > @@ -1327,6 +1328,19 @@ out: > > static void handle_hotplug_event_bridge(acpi_handle handle, u32 type, > > void *context) > > { > > + unsigned long delay = 0; > > + const char *board_name; > > + > > + board_name = dmi_get_system_info(DMI_BOARD_NAME); > > + /* > > + * BIOS on Intel DZ77RE-75K motherboard notifies OS about Thunderbolt > > + * hotplug before devices behind Thunderbolt are ready to be > > + * enumerated. > > + * Let's delay enumeration by 2 seconds. > > + */ > > + if (board_name && !strcmp(board_name, "DZ77RE-75K")) > > + delay = 2 * HZ; > > Again, no objection to this patch as-is, but should we make it a bit > more "general" and provide a quirk table to make this type of fix easier > for other motherboards? Shouldn't we also match on a manufacturer field > as well as the board_name? The kernel provides a very easy to match on > any arbritary set of DMI fields for this kind of problem that we could > use here. Something like this (untested): diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 1a2b3ca..c4db634 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -49,6 +49,7 @@ #include #include #include +#include #include "../pci.h" #include "acpiphp.h" @@ -1327,6 +1328,31 @@ out: static void handle_hotplug_event_bridge(acpi_handle handle, u32 type, void *context) { + unsigned long delay = 0; + const struct dmi_system_id *match; + static const struct dmi_system_id sysids[] = { + /* + * BIOS on Intel DZ77RE-75K motherboard notifies OS about + * Thunderbolt hotplug before devices behind Thunderbolt are + * ready to be enumerated. + * Let's delay enumeration by 2 seconds. + */ + { + .ident = "DZ77RE-75K", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, + "Intel Corporation"), + DMI_MATCH(DMI_BOARD_NAME, + "DZ77RE-75K"), + }, + .driver_data = (void *) (2 * HZ), /* delay */ + }, + }; + + match = dmi_first_match(sysids); + if (match) + delay = (unsigned long) match->driver_data; + /* * Currently the code adds all hotplug events to the kacpid_wq * queue when it should add hotplug events to the kacpi_hotplug_wq. @@ -1336,7 +1362,7 @@ static void handle_hotplug_event_bridge(acpi_handle handle, u32 type, * don't deadlock on hotplug actions. */ alloc_acpiphp_hp_work(handle, type, context, - _handle_hotplug_event_bridge, 0); + _handle_hotplug_event_bridge, delay); } static void _handle_hotplug_event_func(struct work_struct *work)