Commit 517fd2b6 authored by Ezequiel Garcia's avatar Ezequiel Garcia Committed by Mauro Carvalho Chehab
Browse files

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: default avatarEzequiel Garcia <ezequiel@collabora.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 97cf50b6

drivers/media/v4l2-core/v4l2-async.c

+66 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>

 */



#include <linux/debugfs.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/i2c.h>
@@ -14,6 +15,7 @@ 
#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/seq_file.h>

#include <linux/slab.h>

#include <linux/types.h>
@@ -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, &notifier_list, list) {

		seq_printf(s, "%s:\n", v4l2_async_notifier_name(notif));

		list_for_each_entry(asd, &notif->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);

}

drivers/media/v4l2-core/v4l2-dev.c

+5 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/debugfs.h>

#include <linux/module.h>

#include <linux/types.h>

#include <linux/kernel.h>
@@ -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);

}

include/media/v4l2-async.h

+8 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/list.h>

#include <linux/mutex.h>



struct dentry;

struct device;

struct device_node;

struct v4l2_device;
@@ -120,6 +121,13 @@ 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.

 *