...

• if (count > size - pos)

• count = size - pos;
  

max() / min()

ok

...

• /* intermediate buffer size must be u32 multiple */
• size = (count + 3) & ~3;

Hmm, don't we have something like round_up()?

yes, round_up (count, 4) would work.

...

• dfse->dfsentry = debugfs_create_file(name, 0444, sdev->debugfs_root,

• 			     dfse, &sof_dfs_fops);
  

• if (!dfse->dfsentry) {

• dev_err(sdev->dev, "error: cannot create debugfs entry.\n");
  

• return -ENODEV;
  

• }

We shouldn't rely on debugfs files. Thus, error checking needs to be removed.

Something like

void () { struct dentry *d;

d = debugfs_...(); if (!d) dev_err(); }

You lost me on this one. The main purpose of this return -ENODEV is to avoid adding more entries if one item failed. It's not different from what our estimeed colleagues did in skl-debug.c

...

• dfse->dfsentry = debugfs_create_file(name, 0444, sdev->debugfs_root,

• 			     dfse, &sof_dfs_fops);
  

• if (!dfse->dfsentry) {

• dev_err(sdev->dev, "error: cannot create debugfs entry.\n");
  

• return -ENODEV;
  

• }

Ditto.

...

• sdev->debugfs_root = debugfs_create_dir("sof", NULL);
• if (IS_ERR_OR_NULL(sdev->debugfs_root)) {

• dev_err(sdev->dev, "error: failed to create debugfs directory\n");
  

• return -EINVAL;
  

• }
• /* create debugFS files for platform specific MMIO/DSP memories */
• for (i = 0; i < ops->debug_map_count; i++) {

• map = &ops->debug_map[i];
  

• err = snd_sof_debugfs_io_create_item(sdev, sdev->bar[map->bar] +
  

• 				  map->offset, map->size,
  

• 				  map->name);
  

• if (err < 0)
  

• 	dev_err(sdev->dev, "error: cannot create debugfs for %s\n",
  

• 		map->name);
  

Ditto (error message dups above).

...

• }
• return err;

or maybe that's the issue, we shouldn't return an error on the init proper, but I see nothing wrong in stopping when things go south.

...

+} +EXPORT_SYMBOL(snd_sof_dbg_init);