Re: [PATCH] tty: Add EXTPROC support for LINEMODE

[Howard Chu <hyc@symas.com>]

Alan Cox wrote:
>>>> For Alpha this value should match OSF if possible.
>>
>> OSF didn't define this flag, nor did it assign that particular bit to any
>> purpose. Is that good enough?
>
> Fine
>
>>> Are you suggesting that this is completely unfixable/unworkable? Would it be
>>> sufficient to use kernel_termios_to_user_termios() ?
>
> I don't see a way to fix it sanely
>
>>>
>> Actually using kernel_termios_to_user_termios_1(). In all supported
>> architectures this structure is basically aligned with but smaller than the
>> userland struct termios.
>
> The relationship isn't quite so simple and it may change in the future,
> so this seems to be a very bad idea. Besides which syscalls are *cheap*
> so simply notifying someone to reread the terminal data they care about
> should be fine. In that sense it seems SVR4 got it right.

OK. I'm fine with only setting a bit in the packet header, and letting the 
application do an ioctl/tcgetattr to discover the actual state. Next question 
is, should this bit still be called TIOCPKT_IOCTL (which BSD uses) or should 
it be called something else, since the behavior is not the same as BSD?

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/