[GitHub] [incubator-nuttx] masayuki2009 commented on a change in pull request #1196: Refactor audio

[GitBox <gi...@apache.org>]

masayuki2009 commented on a change in pull request #1196:
URL: https://github.com/apache/incubator-nuttx/pull/1196#discussion_r435653888



##########
File path: drivers/audio/audio_null.c
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@@ -771,11 +772,12 @@ static int null_ioctl(FAR struct audio_lowerhalf_s *dev, int cmd,
 #endif
 
       default:
+        ret = -EINVAL;

Review comment:
       > This NuttX convention is that if the ioctl functions does not recognize the command, it returns ENOTTY, not EINVAL.
   > 
   > See https://en.wikipedia.org/wiki/Not_a_typewriter which is how NutX does things in ioctls too.
   
   Hi @patacongo,
   
   Thanks for the comments. 
   Actually, I checked it with 'man ioctl' on Ubuntu18.04 and it says that
   
   ```
   ERRORS
          EBADF  fd is not a valid file descriptor.
          EFAULT argp references an inaccessible memory area.
          EINVAL request or argp is not valid.
          ENOTTY fd is not associated with a character special device.
          ENOTTY The specified request does not apply to the kind of object that the file descriptor fd references.
   ```
   
   So I thought we should return EINVAL.
   However in NuttX should we return ENOTTY instead of EINVAL?
   




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