From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753567AbdLMQ2U (ORCPT ); Wed, 13 Dec 2017 11:28:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:40490 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752811AbdLMQ2R (ORCPT ); Wed, 13 Dec 2017 11:28:17 -0500 Date: Wed, 13 Dec 2017 17:28:21 +0100 From: Greg Kroah-Hartman To: Vinod Koul Cc: LKML , ALSA , Mark , Takashi , Pierre , patches.audio@intel.com, alan@linux.intel.com, Charles Keepax , Sagar Dharia , srinivas.kandagatla@linaro.org, plai@codeaurora.org, Sudheer Papothi Subject: Re: [PATCH v5 10/15] soundwire: Add sysfs for SoundWire DisCo properties Message-ID: <20171213162821.GB17132@kroah.com> References: <1512575231-4154-1-git-send-email-vinod.koul@intel.com> <1512575231-4154-11-git-send-email-vinod.koul@intel.com> <20171213091537.GA6269@kroah.com> <20171213095430.GO18649@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171213095430.GO18649@localhost> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 13, 2017 at 03:24:30PM +0530, Vinod Koul wrote: > On Wed, Dec 13, 2017 at 10:15:37AM +0100, Greg Kroah-Hartman wrote: > > On Wed, Dec 06, 2017 at 09:17:06PM +0530, Vinod Koul wrote: > > > It helps to read the properties for understanding and debugging > > > systems, so add sysfs files for SoundWire DisCo properties. > > > > > > TODO: Add ABI files for sysfs > > > > Is this TODO done? > > Nope sorry not yet. But before this get merged will add > > > > + * Base file is: > > > + * properties > > > + * |---- interface-revision > > > + * |---- master-count > > > + * |---- link-N > > > + * |---- clock-stop-modes > > > + * |---- max-clock-frequency > > > + * |---- clock-frequencies > > > + * |---- default-frame-rows > > > + * |---- default-frame-cols > > > + * |---- dynamic-frame-shape > > > + * |---- command-error-threshold > > > + */ > > > > Why nest them so deep? Anyway, that's not really an issue I guess, it's > > your ABI, not mine :) > > well it gives us a hierarchical view. We have N links... That's fine, then make it a real 'struct device' if you want to have a reference counted object. Tie it to your bus, and you are good to go. Don't use a raw kobject as that totaly breaks the device heirachy in the kernel as well as preventing any of these attributes from being accessed by userspace libraries (i.e. libudev.) > > > + > > > +struct sdw_master_sysfs { > > > + struct kobject kobj; > > > + struct sdw_bus *bus; > > > > Huh? Why do you need to use kobjects? > > > > When you switch from using a 'struct device' and hang a kobject off of > > it, that's a huge signal that something is wrong here. That kobject > > will now no longer be part of the device "chain" in the system, uevents > > will get odd, and other strange things can happen. > > > > Why can't you just use "normal" attributes attached to the device? You > > shouldn't need a kobject here. What am I missing? > > Okay my understanding might be incorrect then. So we can have N links in > the system and each link would have a kobject for "link-N". Not sure how > device attributes would do link-N/clock-stop-modes and so on, if they can > let me know how and I will surely change that. You can create a subdirectory for attributes quite easily. If you don't want to make it a "full" object, and all you care about is the subdirectory, then do it that way. Otherwise use a 'struct device' please. thanks, greg k-h