From patchwork Mon Jan 4 17:48:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ezequiel Garcia X-Patchwork-Id: 357202 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, URIBL_BLOCKED, USER_AGENT_GIT 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 142B3C433DB for ; Mon, 4 Jan 2021 17:49:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D98CD206B2 for ; Mon, 4 Jan 2021 17:49:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727040AbhADRtc (ORCPT ); Mon, 4 Jan 2021 12:49:32 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:34212 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726939AbhADRtc (ORCPT ); Mon, 4 Jan 2021 12:49:32 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 54F101F44C45 From: Ezequiel Garcia To: linux-media@vger.kernel.org, Hans Verkuil Cc: kernel@collabora.com, Laurent Pinchart , Sakari Ailus , Ezequiel Garcia Subject: [PATCH v2] media: v4l2-async: Add waiting subdevices debugfs Date: Mon, 4 Jan 2021 14:48:40 -0300 Message-Id: <20210104174840.144958-1-ezequiel@collabora.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org There is currently little to none information available about the reasons why a v4l2-async device hasn't probed completely. Inspired by the "devices_deferred" debugfs file, add a file to list information about the subdevices that are on waiting lists, for each notifier. This is useful to debug v4l2-async subdevices and notifiers, for instance when doing device bring-up. For instance, a typical output would be: $ cat /sys/kernel/debug/video4linux/pending_async_subdevices ipu1_csi1: [fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi1_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi1_mux ipu1_csi0: [fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi0_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi0_mux imx6-mipi-csi2: [fwnode] dev=1-003c, node=/soc/bus@2100000/i2c@21a4000/camera@3c imx-media: Note that match-type "custom" prints no information. Since there are no in-tree users of this match-type, the implementation doesn't bother. Signed-off-by: Ezequiel Garcia Reviewed-by: Laurent Pinchart --- v2: * Print fwnode path, as suggested by Sakari. * Print the subdevices under their corresponding notifier. * Rename the file as suggested by Laurent. --- drivers/media/v4l2-core/v4l2-async.c | 66 ++++++++++++++++++++++++++++ drivers/media/v4l2-core/v4l2-dev.c | 5 +++ include/media/v4l2-async.h | 9 ++++ 3 files changed, 80 insertions(+) diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index e3ab003a6c85..d779808abb3b 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -5,6 +5,7 @@ * Copyright (C) 2012-2013, Guennadi Liakhovetski */ +#include #include #include #include @@ -14,6 +15,7 @@ #include #include #include +#include #include #include @@ -837,3 +839,67 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) mutex_unlock(&list_lock); } EXPORT_SYMBOL(v4l2_async_unregister_subdev); + +static void print_waiting_subdev(struct seq_file *s, + struct v4l2_async_subdev *asd) +{ + switch (asd->match_type) { + case V4L2_ASYNC_MATCH_CUSTOM: + seq_puts(s, " [custom]\n"); + break; + case V4L2_ASYNC_MATCH_DEVNAME: + seq_printf(s, " [devname] %s\n", asd->match.device_name); + break; + case V4L2_ASYNC_MATCH_I2C: + seq_printf(s, " [i2c] %d-%04x\n", asd->match.i2c.adapter_id, + asd->match.i2c.address); + break; + case V4L2_ASYNC_MATCH_FWNODE: { + struct fwnode_handle *fwnode = asd->match.fwnode; + + if (fwnode_graph_is_endpoint(fwnode)) + fwnode = fwnode_graph_get_port_parent(fwnode); + + seq_printf(s, " [fwnode] dev=%s, node=%pfw\n", + fwnode->dev ? dev_name(fwnode->dev) : "nil", + fwnode); + break; + } + } +} + +static const char * +v4l2_async_notifier_name(struct v4l2_async_notifier *notifier) +{ + if (notifier->v4l2_dev) + return notifier->v4l2_dev->name; + else if (notifier->sd) + return notifier->sd->name; + else + return "nil"; +} + +static int pending_subdevs_show(struct seq_file *s, void *data) +{ + struct v4l2_async_notifier *notif; + struct v4l2_async_subdev *asd; + + mutex_lock(&list_lock); + + list_for_each_entry(notif, ¬ifier_list, list) { + seq_printf(s, "%s:\n", v4l2_async_notifier_name(notif)); + list_for_each_entry(asd, ¬if->waiting, list) + print_waiting_subdev(s, asd); + } + + mutex_unlock(&list_lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(pending_subdevs); + +void v4l2_async_debug_init(struct dentry *debugfs_dir) +{ + debugfs_create_file("pending_async_subdevices", 0444, debugfs_dir, NULL, + &pending_subdevs_fops); +} diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index a593ea0598b5..8d3813e6ab56 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include #include @@ -37,6 +38,7 @@ __func__, ##arg); \ } while (0) +static struct dentry *v4l2_debugfs_dir; /* * sysfs stuff @@ -1113,6 +1115,8 @@ static int __init videodev_init(void) return -EIO; } + v4l2_debugfs_dir = debugfs_create_dir("video4linux", NULL); + v4l2_async_debug_init(v4l2_debugfs_dir); return 0; } @@ -1120,6 +1124,7 @@ static void __exit videodev_exit(void) { dev_t dev = MKDEV(VIDEO_MAJOR, 0); + debugfs_remove_recursive(v4l2_debugfs_dir); class_unregister(&video_class); unregister_chrdev_region(dev, VIDEO_NUM_DEVICES); } diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h index 0e04b5b2ebb0..abc85474bb3b 100644 --- a/include/media/v4l2-async.h +++ b/include/media/v4l2-async.h @@ -8,9 +8,11 @@ #ifndef V4L2_ASYNC_H #define V4L2_ASYNC_H +#include #include #include +struct dentry; struct device; struct device_node; struct v4l2_device; @@ -137,6 +139,13 @@ struct v4l2_async_notifier { struct list_head list; }; +/** + * v4l2_async_debug_init - Initialize debugging tools. + * + * @debugfs_dir: pointer to the parent debugfs &struct dentry + */ +void v4l2_async_debug_init(struct dentry *debugfs_dir); + /** * v4l2_async_notifier_init - Initialize a notifier. *