From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C203C11D2F for ; Mon, 24 Feb 2020 16:46:49 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 66EAC20637 for ; Mon, 24 Feb 2020 16:46:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 66EAC20637 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E5C256E5B4; Mon, 24 Feb 2020 16:46:48 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3DDDC6E5B4 for ; Mon, 24 Feb 2020 16:46:48 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP; 24 Feb 2020 08:46:47 -0800 X-IronPort-AV: E=Sophos;i="5.70,480,1574150400"; d="scan'208";a="230707325" Received: from pmulhall-mobl.ger.corp.intel.com (HELO [10.251.85.135]) ([10.251.85.135]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 24 Feb 2020 08:46:46 -0800 To: Andi Shyti References: <20200219190223.16972-1-andi.shyti@intel.com> <20200219193020.17673-1-andi.shyti@intel.com> <20200224163029.GA1579@intel.intel> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <421b0bd8-6bc6-e6c2-7e08-6d112c57a860@linux.intel.com> Date: Mon, 24 Feb 2020 16:46:44 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200224163029.GA1579@intel.intel> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH v5] drm/i915/gt: make a gt sysfs group and move power management files X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Intel GFX Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 24/02/2020 16:30, Andi Shyti wrote: >>> +void intel_gt_sysfs_register(struct intel_gt *gt) >>> +{ >>> + struct kobject *parent = kobject_get(gt_get_parent_obj(gt)); >>> + int ret; >>> + >>> + ret = kobject_init_and_add(>->sysfs_root, >>> + &sysfs_gt_ktype, >>> + parent, "gt"); >>> + if (ret) { >>> + drm_err(>->i915->drm, "failed to initialize sysfs file\n"); >> >> I'd perhaps pin point the failure more by s/file/GT sysfs root/. > > OK > >>> + kobject_put(>->sysfs_root); >> >> Is the reference needed for the registration steps? I am thinking if you >> could kobject_get only once everything worked to simplify. > > I haven't really understood what you mean here. Are you saying > that kobject_put not needed? in the lib/kobject.c it says as > comment to kobject_init_and_add(): > > " > * If this function returns an error, kobject_put() must be called to > * properly clean up the memory associated with the object. This is the > * same type of error handling after a call to kobject_add() and kobject > * lifetime rules are the same here. > */ > " My mistake, I confused the two objects. >>> + ret = sysfs_create_file(>->sysfs_root, &dev_attr_gt_info.attr); >>> + if (ret) >>> + drm_err(>->i915->drm, "failed to create sysfs gt info files\n"); >>> + >>> + intel_gt_sysfs_pm_init(gt, >->sysfs_root); >> >> If you put this first you can avoid the goto I think which makes the >> function smaller. > > True! > >>> +void intel_gt_sysfs_unregister(struct intel_gt *gt) >>> +{ >>> + struct kobject *parent = gt_get_parent_obj(gt); >>> + >>> + /* >>> + * the name gt tells us wether sysfs_root >>> + * object was initialized properly >>> + */ >>> + if (!strcmp(gt->sysfs_root.name, "gt")) >>> + kobject_put(>->sysfs_root); >> >> Slightly nicer would be looking at kobj->state_initialized for this check I >> think. Or even kref_get_unless_zero on kobj->kref? Ugliness there is double >> put on sucess which makes me ask whether holding a reference on parent is >> even needed? It can't go away so perhaps it isn't. > > I'd rather use the state_initialized, even though I don't trust > its value if the kobject has failed to initialise earlier, I > trust it only if it's '1', maybe I'm paranoic. But is the reference even needed? Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx