On Thu, Aug 03, 2017 at 04:37:18PM +0800, Chunfeng Yun wrote:
> +static ssize_t ssusb_vbus_write(struct file *file,
> + const char __user *ubuf, size_t count, loff_t *ppos)
> +{
> + struct seq_file *sf = file->private_data;
> + struct ssusb_mtk *ssusb = sf->private;
> + struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
> + char buf[16];
> +
> + if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
> + return -EFAULT;
> +
> + if (!strncmp(buf, "on", 2)) {
> + ssusb_set_vbus(otg_sx, 1);
> + } else if (!strncmp(buf, "off", 3)) {
> + ssusb_set_vbus(otg_sx, 0);
kstrtobool() is better to use here.
> +static int ssusb_debugfs_init(struct ssusb_mtk *ssusb)
> {
> struct dentry *root;
> struct dentry *file;
>
> root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
> if (IS_ERR_OR_NULL(root)) {
That test is wrong, you should never need to care about the return value
of a debugfs call. You can always just use it in your next call (if it
is a dentry *), or just ignore it.
> - if (!root)
> - dev_err(ssusb->dev, "create debugfs root failed\n");
> - return;
> + dev_err(ssusb->dev, "create debugfs root failed\n");
> + goto err_dbgfs;
> }
> ssusb->dbgfs_root = root;
>
> - file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
> - ssusb, &ssusb_mode_fops);
> - if (!file)
> - dev_dbg(ssusb->dev, "create debugfs mode failed\n");
> + file = debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
> + if (!file) {
> + dev_err(ssusb->dev, "create debugfs mode failed\n");
Same here, do not care, as it does not matter. Actually, you don't even
need to keep the file pointer around, right?
> + goto err_dbgfs;
> + }
> +
> + file = debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
> + if (!file) {
Same here, you don't care if debugfs fails or not, it should never
affect your code flow.
And don't you need to remove the directory when your module/hardware is
removed? I don't see that happening here as you are not saving root off
anywhere.
thanks,
greg k-h
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