media: siano: Drop unnecessary error check for debugfs_create_dir/file()

Both debugfs_create_dir() and debugfs_create_file() return ERR_PTR
and never return NULL.

As Hans suggested, this patch removes the error checking for both
debugfs_create_dir() and debugfs_create_file() in smsdvb_debugfs_create().
This is because the DebugFS kernel API is developed in a way that the
caller can safely ignore the errors that occur during the creation of
DebugFS nodes. The debugfs APIs have a IS_ERR() judge in start_creating()
which can handle it gracefully. So these checks are unnecessary.

And as Hans pointed out, it's much better to first allocate debug_data
before calling debugfs_create_dir, which need not to clean anything up in
that case.

Fixes: 503efe5cfc9f ("[media] siano: split debugfs code into a separate file")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/common/siano/smsdvb-debugfs.c b/drivers/media/common/siano/smsdvb-debugfs.c
index e0beefd80d7bc9b7a70cd0e09acbea184044a6d0..73990e469df9da993af59e6ae0ac1c62e76b4a72 100644 (file)
--- a/drivers/media/common/siano/smsdvb-debugfs.c
+++ b/drivers/media/common/siano/smsdvb-debugfs.c
@@ -353,31 +353,21 @@ static const struct file_operations debugfs_stats_ops = {
 int smsdvb_debugfs_create(struct smsdvb_client_t *client)
 {
        struct smscore_device_t *coredev = client->coredev;
-       struct dentry *d;
        struct smsdvb_debugfs *debug_data;
 
        if (!smsdvb_debugfs_usb_root || !coredev->is_usb_device)
                return -ENODEV;
 
-       client->debugfs = debugfs_create_dir(coredev->devpath,
-                                            smsdvb_debugfs_usb_root);
-       if (IS_ERR_OR_NULL(client->debugfs)) {
-               pr_info("Unable to create debugfs %s directory.\n",
-                       coredev->devpath);
-               return -ENODEV;
-       }
-
-       d = debugfs_create_file("stats", S_IRUGO | S_IWUSR, client->debugfs,
-                               client, &debugfs_stats_ops);
-       if (!d) {
-               debugfs_remove(client->debugfs);
-               return -ENOMEM;
-       }
-
        debug_data = kzalloc(sizeof(*client->debug_data), GFP_KERNEL);
        if (!debug_data)
                return -ENOMEM;
 
+       client->debugfs = debugfs_create_dir(coredev->devpath,
+                                            smsdvb_debugfs_usb_root);
+
+       debugfs_create_file("stats", S_IRUGO | S_IWUSR, client->debugfs,
+                           client, &debugfs_stats_ops);
+
        client->debug_data        = debug_data;
        client->prt_dvb_stats     = smsdvb_print_dvb_stats;
        client->prt_isdb_stats    = smsdvb_print_isdb_stats;