From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754381AbdA3UnN (ORCPT ); Mon, 30 Jan 2017 15:43:13 -0500 Received: from rcdn-iport-7.cisco.com ([173.37.86.78]:44459 "EHLO rcdn-iport-7.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbdA3UnL (ORCPT ); Mon, 30 Jan 2017 15:43:11 -0500 X-Greylist: delayed 355 seconds by postgrey-1.27 at vger.kernel.org; Mon, 30 Jan 2017 15:43:11 EST X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0BTAgC6o49Y/4gNJK1dGwEBAQMBAQEJA?= =?us-ascii?q?QEBg1RhKl+DVYoJpzaCDC6IHD8YAQIBAQEBAQEBYiiFExV2AiYCXwEMCAEBiV0?= =?us-ascii?q?Oq0CCJYsWAQEBAQEBAQMBAQEBAQEBHAUTeIVAggWFdoEwgxOCXwWQL4slhmeLF?= =?us-ascii?q?Io4hj+Sfx84OmETCBUVhxVVBIVzgjoBAQE?= X-IronPort-AV: E=Sophos;i="5.33,312,1477958400"; d="scan'208";a="200480254" To: "xe-kernel@external.cisco.com" , Greg Kroah-Hartman , Jean Delvare , Guenter Roeck , lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org From: Daniel Walker Subject: unstable /sys interface from hmon Message-ID: <99aae36e-ddfd-dcd2-e544-9c28ae373959@cisco.com> Date: Mon, 30 Jan 2017 12:37:14 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Auto-Response-Suppress: DR, OOF, AutoReply Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Cisco recently upgraded to kernel 4.4.. We have applications which use the /sys interfaces for some hmon drivers. We found that the following patches, https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bab2243ce1897865e31ea6d59b0478391f51812b https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c3b7cddc70075d525db6b3068d8b2b9158eedc84 Altered the interface as seen from userspace. These patches changed the paths in the following way, Before, /sys/bus/i2c/devices/14-0050/ After, /sys/bus/i2c/devices/14-0050/hwmon/hwmon7 My impression was that /sys was suppose to be stable, and debugfs was unstable. I'm not sure what the current guidelines are for this, but we would request that hmon drivers maintain a stable interface from /sys. This change has cause upgrade issues for us which we would like to avoid in the future. A patch to add in a compatibility layer would be welcome. Daniel