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057e212eae
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
106 lines
2.5 KiB
C
106 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* uvc_debugfs.c -- USB Video Class driver - Debugging support
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*
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* Copyright (C) 2011
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* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
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*/
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#include <linux/module.h>
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#include <linux/debugfs.h>
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#include <linux/slab.h>
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#include <linux/usb.h>
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#include "uvcvideo.h"
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/* -----------------------------------------------------------------------------
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* Statistics
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*/
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#define UVC_DEBUGFS_BUF_SIZE 1024
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struct uvc_debugfs_buffer {
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size_t count;
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char data[UVC_DEBUGFS_BUF_SIZE];
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};
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static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
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{
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struct uvc_streaming *stream = inode->i_private;
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struct uvc_debugfs_buffer *buf;
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buf = kmalloc(sizeof(*buf), GFP_KERNEL);
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if (buf == NULL)
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return -ENOMEM;
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buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
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file->private_data = buf;
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return 0;
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}
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static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
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size_t nbytes, loff_t *ppos)
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{
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struct uvc_debugfs_buffer *buf = file->private_data;
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return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
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buf->count);
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}
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static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
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{
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kfree(file->private_data);
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file->private_data = NULL;
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return 0;
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}
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static const struct file_operations uvc_debugfs_stats_fops = {
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.owner = THIS_MODULE,
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.open = uvc_debugfs_stats_open,
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.llseek = no_llseek,
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.read = uvc_debugfs_stats_read,
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.release = uvc_debugfs_stats_release,
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};
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/* -----------------------------------------------------------------------------
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* Global and stream initialization/cleanup
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*/
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static struct dentry *uvc_debugfs_root_dir;
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void uvc_debugfs_init_stream(struct uvc_streaming *stream)
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{
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struct usb_device *udev = stream->dev->udev;
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char dir_name[33];
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if (uvc_debugfs_root_dir == NULL)
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return;
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snprintf(dir_name, sizeof(dir_name), "%u-%u-%u", udev->bus->busnum,
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udev->devnum, stream->intfnum);
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stream->debugfs_dir = debugfs_create_dir(dir_name,
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uvc_debugfs_root_dir);
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debugfs_create_file("stats", 0444, stream->debugfs_dir, stream,
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&uvc_debugfs_stats_fops);
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}
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void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
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{
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debugfs_remove_recursive(stream->debugfs_dir);
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stream->debugfs_dir = NULL;
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}
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void uvc_debugfs_init(void)
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{
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uvc_debugfs_root_dir = debugfs_create_dir("uvcvideo", usb_debug_root);
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}
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void uvc_debugfs_cleanup(void)
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{
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debugfs_remove_recursive(uvc_debugfs_root_dir);
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}
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