[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4C1A923B.4070701@symas.com>
Date: Thu, 17 Jun 2010 14:23:07 -0700
From: Howard Chu <hyc@...as.com>
To: Alan Cox <alan@...rguk.ukuu.org.uk>
CC: linux-kernel@...r.kernel.org, Greg KH <greg@...ah.com>
Subject: Re: [PATCH] tty: Add EXTPROC support for LINEMODE
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/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists