On Thu, 2017-08-03 at 09:01 -0700, Greg Kroah-Hartman wrote: > On Thu, Aug 03, 2017 at 09:00:57AM -0700, Greg Kroah-Hartman wrote: > > 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. Ok > > > > > +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. Ok, I'll just test NULL pointer, and ignore other ERROR value > > > > > - 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? Yes, you are 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. Ok Thanks a lot > > > > 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. > > Oh nevermind, you do save it, sorry for the noise... > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html