From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751656AbdFAKJt (ORCPT ); Thu, 1 Jun 2017 06:09:49 -0400 Received: from mga09.intel.com ([134.134.136.24]:1871 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751346AbdFAKJr (ORCPT ); Thu, 1 Jun 2017 06:09:47 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,279,1493708400"; d="scan'208";a="1155304029" Date: Thu, 1 Jun 2017 13:09:40 +0300 From: Mika Westerberg To: Jean Delvare Cc: Linus Walleij , Heikki Krogerus , Andy Shevchenko , Dmitry Torokhov , Wei Yongjun , bbaude@redhat.com, mildred-bug.kernel@mildred.fr, barnacs@justletit.be, lvuksta@gmail.com, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, Kelly French Subject: Re: [PATCH v2 1/3] firmware: dmi: Add DMI_PRODUCT_FAMILY identification string Message-ID: <20170601100940.GJ2784@lahna.fi.intel.com> References: <20170517102514.89744-1-mika.westerberg@linux.intel.com> <20170517102514.89744-2-mika.westerberg@linux.intel.com> <20170601112926.78fa218a@endymion> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170601112926.78fa218a@endymion> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 01, 2017 at 11:29:26AM +0200, Jean Delvare wrote: > Hi all, > > Sorry for the late reply. > > On Wed, 17 May 2017 13:25:12 +0300, Mika Westerberg wrote: > > Sometimes it is more convenient to be able to match a whole family of > > products, like in case of bunch of Chromebooks based on Intel_Strago to > > apply a driver quirk instead of quirking each machine one-by-one. > > > > This adds support for DMI_PRODUCT_FAMILY identification string and also > > exports it to the userspace through sysfs attribute just like the > > existing ones. > > dmidecode currently provides no direct access to this string. Do you > think it should? Yeah, why not. I always just run "dmidecode" without any arguments and that field is printed nicely among others :) > > Suggested-by: Dmitry Torokhov > > Signed-off-by: Mika Westerberg > > --- > > drivers/firmware/dmi-id.c | 2 ++ > > drivers/firmware/dmi_scan.c | 1 + > > include/linux/mod_devicetable.h | 1 + > > 3 files changed, 4 insertions(+) > > > > diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c > > index 44c01390d035..dc269cb288c2 100644 > > --- a/drivers/firmware/dmi-id.c > > +++ b/drivers/firmware/dmi-id.c > > (...) > > @@ -191,6 +192,7 @@ static void __init dmi_id_init_attr_table(void) > > ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION); > > ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL); > > ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID); > > + ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY); > > Alignment, please! The patch is already applied and I suppose merged in v4.12-rc3+. Should I send a fixup patch to fix this? > > > ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR); > > ADD_DMI_ATTR(board_name, DMI_BOARD_NAME); > > ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION); > > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > > index 54be60ead08f..93f7acdaac7a 100644 > > --- a/drivers/firmware/dmi_scan.c > > +++ b/drivers/firmware/dmi_scan.c > > @@ -430,6 +430,7 @@ static void __init dmi_decode(const struct dmi_header *dm, void *dummy) > > dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6); > > dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7); > > dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8); > > + dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26); > > This field only exists since SMBIOS 2.4. For older implementations, you > are accessing a random location of the DMI table. Most likely you'll > hit a character in one of the strings associated with the system > information structure. In turn this character will be interpreted as a > DMI string number. With some luck, number will be >= 32, so you'll get > a non-existent string and dmi_string will return "". But you could hit > a string terminator (0) and return the 1st string of the structure > instead (most likely the system manufacturer.) > > Note that the problem is not specific to this field, it is just more > likely to break because all other fields are defined by SMBIOS 2.0, or > for the product UUID, SMBIOS 2.1. The fact that all dmi_save_* > functions blindly assume that the structure is long enough to contain > all the fields they want to save is problematic. This should be fixed > separately. I see. Since you are more familiar with the DMI code, do you have time to do that or should I try? Thanks.