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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 3B31FC5CFC1 for ; Tue, 19 Jun 2018 18:34:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03B6C20693 for ; Tue, 19 Jun 2018 18:34:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03B6C20693 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030394AbeFSSeB (ORCPT ); Tue, 19 Jun 2018 14:34:01 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:36166 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030279AbeFSSeA (ORCPT ); Tue, 19 Jun 2018 14:34:00 -0400 Received: by mail-wr0-f196.google.com with SMTP id f16-v6so664636wrm.3 for ; Tue, 19 Jun 2018 11:33:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=QtxUyfLucKOe/dBeI7a/kfctRhipQUIczmfKo7SJ/bY=; b=RVOwpto3LJq3CX42IgOAFPDCOZ3oZhZRv5taRi8UJXKaLDvqsr8wt73EXwaNHFWK02 wtW93pWxWZiKI3kGlFHcU7WQgHgIGmMKg1apHaCax9u59WYT3//c8W1GpxNf6Dg7jSUR wOWNQRBxWbzCgHNKbGrcP7UJSNxqJiqy0jDrel3TbTx8L7lDo2tj5JYXdGoJThKObotG fYPdzVWlqb4cpOzXN2yPoEGsTOnKfQ1ZuYIAEHOqUa184ag6ENkdLkgpRH0SgM3W9nT9 k9RFvyRq08GDYJCumqkzmrv8Avk0d3xNLjdKD0tSlwepQUBMaSXisv+EOu1O/8ix4FVB Irag== X-Gm-Message-State: APt69E2yDhtdfQhvzQEnrj7aYsOlG5bqlprvCqWai0JyWDsrvy7XBYYe FqmV9JbDzaoJ7OCClGqpMCJzBKE2ggU= X-Google-Smtp-Source: ADUXVKJICeqJHg7CCYgoyqQ9FGWSYLnvlOYQl+nNTyI88WXHz1a+UDt9kqqRy9hFtVGt2pa0jTa4Ow== X-Received: by 2002:adf:ee0e:: with SMTP id y14-v6mr15950700wrn.63.1529433239000; Tue, 19 Jun 2018 11:33:59 -0700 (PDT) Received: from minerva.home ([90.77.100.34]) by smtp.gmail.com with ESMTPSA id 127-v6sm1040104wmk.45.2018.06.19.11.33.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 19 Jun 2018 11:33:58 -0700 (PDT) From: Javier Martinez Canillas To: linux-kernel@vger.kernel.org Cc: Mark Brown , Tomeu Vizoso , linux-arm-kernel@lists.infradead.org, Rob Herring , Javier Martinez Canillas , Greg Kroah-Hartman Subject: [RFC PATCH v2] driver core: add a debugfs entry to show deferred devices Date: Tue, 19 Jun 2018 20:33:56 +0200 Message-Id: <20180619183356.32106-1-javierm@redhat.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For debugging purposes it may be useful to know what are the devices whose probe function was deferred. Add a debugfs entry showing that information. $ cat /sys/kernel/debug/deferred_devices 48070000.i2c:twl@48:bci musb-hdrc.0.auto omapdrm.0 Signed-off-by: Javier Martinez Canillas --- Changes in v2: - Remove unneeded ret variable from deferred_devs_show() drivers/base/dd.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 1435d7281c6..d95bd4636fc 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -224,6 +224,42 @@ void device_unblock_probing(void) driver_deferred_probe_trigger(); } +#if IS_ENABLED(CONFIG_DEBUG_FS) +#include + +static struct dentry *deferred_devices; + +/* + * deferred_devs_show() - Show the devices in the deferred probe pending list. + */ +static int deferred_devs_show(struct seq_file *s, void *data) +{ + struct device_private *curr; + + mutex_lock(&deferred_probe_mutex); + + list_for_each_entry(curr, &deferred_probe_pending_list, deferred_probe) + seq_printf(s, "%s\n", dev_name(curr->device)); + + mutex_unlock(&deferred_probe_mutex); + + return 0; +} + +static int deferred_devs_open(struct inode *inode, struct file *file) +{ + return single_open(file, deferred_devs_show, inode->i_private); +} + +static const struct file_operations deferred_devs_fops = { + .owner = THIS_MODULE, + .open = deferred_devs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */ + /** * deferred_probe_initcall() - Enable probing of deferred devices * @@ -233,6 +269,14 @@ void device_unblock_probing(void) */ static int deferred_probe_initcall(void) { + if (IS_ENABLED(CONFIG_DEBUG_FS)) { + deferred_devices = debugfs_create_file("deferred_devices", + 0444, NULL, NULL, + &deferred_devs_fops); + if (!deferred_devices) + return -ENOMEM; + } + driver_deferred_probe_enable = true; driver_deferred_probe_trigger(); /* Sort as many dependencies as possible before exiting initcalls */ -- 2.17.1