Re: [PATCH 1/1] usb: xhci: Add debugfs interface for xHCI driver

From: Lu Baolu
Date: Sat Jul 29 2017 - 23:05:46 EST


Hi Greg,


On 07/29/2017 09:34 PM, Greg KH wrote:
> On Sat, Jul 29, 2017 at 04:18:03PM +0800, Lu Baolu wrote:
>> +static void xhci_debugfs_create_files(struct xhci_hcd *xhci,
>> + struct xhci_file_map *files,
>> + size_t nentries, void *data,
>> + struct dentry *parent,
>> + const struct file_operations *fops)
>> +{
>> + int i;
>> + struct dentry *file;
>> +
>> + for (i = 0; i < nentries; i++) {
>> + file = debugfs_create_file(files[i].name, 0444,
>> + parent, data, fops);
>> + if (IS_ERR_OR_NULL(file))
>> + break;
> There's no need to ever check the return value of a debugfs_ function,
> there's nothing you can do here, just keep calling it :)
>
> And you will not get an error, you will only get NULL if there is an
> error, as the only error you would get is if debugfs was not enabled.
>
>> +static struct dentry *xhci_debugfs_create_ring_dir(struct xhci_hcd *xhci,
>> + struct xhci_ring *ring,
>> + const char *name,
>> + struct dentry *parent)
>> +{
>> + struct dentry *dir;
>> +
>> + dir = debugfs_create_dir(name, parent);
>> + if (IS_ERR_OR_NULL(dir))
>> + return NULL;
> Same here. Just keep going, you don't care about the return value, but
> you can use it safely no matter what.
>
>
> Same for other places in this patch as well.

Thanks for review. I will correct them in a v2 patch.

Best regards,
Lu Baolu