Hi, Here is a code fragment, which comments is unnessary? I think the all the comments should be remove because the comments should show "What to do rather than "How to do?". Am I right? /************************************************************************ * Unit flag definitions for un_flags. ************************************************************************/ #define UN_ISOPEN 0x0001 /* Device is open */ #define UN_CLOSING 0x0002 /* Line is being closed */ #define UN_IMM 0x0004 /* Service immediately */ #define UN_BUSY 0x0008 /* Some work this channel */ #define UN_BREAKI 0x0010 /* Input break received */ #define UN_PWAIT 0x0020 /* Printer waiting for terminal */ #define UN_TIME 0x0040 /* Waiting on time */ #define UN_EMPTY 0x0080 /* Waiting output queue empty */ #define UN_LOW 0x0100 /* Waiting output low water mark*/ #define UN_EXCL_OPEN 0x0200 /* Open for exclusive use */ #define UN_WOPEN 0x0400 /* Device waiting for open */ #define UN_WIOCTL 0x0800 /* Device waiting for open */ #define UN_HANGUP 0x8000 /* Carrier lost */ struct device; /************************************************************************ * Structure for terminal or printer unit. ************************************************************************/ struct un_t { int magic; /* Unit Magic Number. */ struct channel_t *un_ch; ulong un_time; uint un_type; uint un_open_count; /* Counter of opens to port */ struct tty_struct *un_tty;/* Pointer to unit tty structure */ uint un_flags; /* Unit flags */ wait_queue_head_t un_flags_wait; /* Place to sleep to wait on unit */ uint un_dev; /* Minor device number */ struct device *un_sysfs; };