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 67634C433EF for ; Tue, 19 Jun 2018 18:21:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F5B420693 for ; Tue, 19 Jun 2018 18:21:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F5B420693 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 S967234AbeFSSVG (ORCPT ); Tue, 19 Jun 2018 14:21:06 -0400 Received: from mail-wr0-f193.google.com ([209.85.128.193]:34324 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966738AbeFSSVE (ORCPT ); Tue, 19 Jun 2018 14:21:04 -0400 Received: by mail-wr0-f193.google.com with SMTP id a12-v6so640708wro.1 for ; Tue, 19 Jun 2018 11:21:04 -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=F2OcYT/MOlc0iq2dBErH7pItRAqGbgn8aaiSWnOr4PU=; b=gKUXCnb0EHjTDbYZETmh4cnYF2iW/VOzFNW/jqZfDLrNG0KsDBUjKEmNGzC4e6eDYT UCsOaRjy/otb1kel7d3ZMawLTrO47WClc9OpE10ktEyMEd3e+nAA4LCkLtk2h1QcbKcH EzFVGJ757m50GPseF6rI+YWXIHhvZpzSUcvwGWERLFzxVBDf1tnHJz0CBecrWHHUDzyJ ABE75lr8yTnnZEgZM4v6PpQi/lIzY4jXNdAzBhN5x+j+GA4wA2uRnnuOtp+zk4knWYV7 nPgRfk8U0grQzTof5yL8csTQsFrtOcfr+zCqr4yGREXsd+T+30b0XcyRKchCE9sb/uN2 vLHg== X-Gm-Message-State: APt69E3tQyc/LKqTwSwaFkZBh1A2yq1zofEeopJ6DxtgGJl3mSCZJ35J QxRPYiKNnDJM0rjUWXWwEms8vQhn5p8= X-Google-Smtp-Source: ADUXVKJxY5IiyzcoEB0BkTPu78CrJFupW0CYeW6PgL1EBg0OO8h2T7nxWdQRMCYh10B1ztSPYA9Pdg== X-Received: by 2002:adf:878c:: with SMTP id b12-v6mr15708251wrb.92.1529432463497; Tue, 19 Jun 2018 11:21:03 -0700 (PDT) Received: from minerva.home ([90.77.100.34]) by smtp.gmail.com with ESMTPSA id l84-v6sm1060216wmi.3.2018.06.19.11.21.02 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 19 Jun 2018 11:21:02 -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] driver core: add a debugfs entry to show deferred devices Date: Tue, 19 Jun 2018 20:20:51 +0200 Message-Id: <20180619182051.26478-1-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 --- drivers/base/dd.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 1435d7281c6..98a3ab4a852 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -224,6 +224,43 @@ 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; + int ret = 0; + + 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 ret; +} + +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 +270,14 @@ 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