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829682b3db
debugfs_remove_recursive() accepts a NULL parameter and returns immediately, there's no need for a NULL check in the caller. This issue was detected with the help of Coccinelle. [Reword commit message, address uvc_debugfs_cleanup_stream()] Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
129 lines
3.1 KiB
C
129 lines
3.1 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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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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struct dentry *dent;
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char dir_name[32];
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if (uvc_debugfs_root_dir == NULL)
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return;
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sprintf(dir_name, "%u-%u", udev->bus->busnum, udev->devnum);
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dent = debugfs_create_dir(dir_name, uvc_debugfs_root_dir);
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if (IS_ERR_OR_NULL(dent)) {
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uvc_printk(KERN_INFO, "Unable to create debugfs %s "
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"directory.\n", dir_name);
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return;
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}
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stream->debugfs_dir = dent;
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dent = debugfs_create_file("stats", 0444, stream->debugfs_dir,
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stream, &uvc_debugfs_stats_fops);
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if (IS_ERR_OR_NULL(dent)) {
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uvc_printk(KERN_INFO, "Unable to create debugfs stats file.\n");
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uvc_debugfs_cleanup_stream(stream);
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return;
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}
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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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struct dentry *dir;
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dir = debugfs_create_dir("uvcvideo", usb_debug_root);
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if (IS_ERR_OR_NULL(dir)) {
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uvc_printk(KERN_INFO, "Unable to create debugfs directory\n");
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return;
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}
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uvc_debugfs_root_dir = dir;
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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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