From 517fd2b6a058bc4f23735ab9a9e6b0d5c56876d1 Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Fri, 8 Jan 2021 18:17:28 +0100 Subject: media: v4l2-async: Add waiting subdevices debugfs There is currently little to no 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: Signed-off-by: Ezequiel Garcia Reviewed-by: Laurent Pinchart Tested-by: Kieran Bingham Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-async.c | 66 ++++++++++++++++++++++++++++++++++++ drivers/media/v4l2-core/v4l2-dev.c | 5 +++ 2 files changed, 71 insertions(+) (limited to 'drivers/media') diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index 3c141ba4f6d4..3db8e2a92982 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 @@ -831,3 +833,67 @@ 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_DEVNAME: + seq_printf(s, " [devname] dev=%s\n", asd->match.device_name); + break; + case V4L2_ASYNC_MATCH_I2C: + seq_printf(s, " [i2c] dev=%d-%04x\n", asd->match.i2c.adapter_id, + asd->match.i2c.address); + break; + case V4L2_ASYNC_MATCH_FWNODE: { + struct fwnode_handle *devnode, *fwnode = asd->match.fwnode; + + devnode = fwnode_graph_is_endpoint(fwnode) ? + fwnode_graph_get_port_parent(fwnode) : + fwnode_handle_get(fwnode); + + seq_printf(s, " [fwnode] dev=%s, node=%pfw\n", + devnode->dev ? dev_name(devnode->dev) : "nil", + fwnode); + + fwnode_handle_put(devnode); + 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 f9cff033d0dc..b6a72d297775 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 @@ -38,6 +39,7 @@ __func__, ##arg); \ } while (0) +static struct dentry *v4l2_debugfs_dir; /* * sysfs stuff @@ -1118,6 +1120,8 @@ 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; } @@ -1125,6 +1129,7 @@ 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); } -- cgit v1.2.3