Re: Serial custom speed deprecated?

[Michael Poole <mdpoole@troilus.org>]

linux-os \(Dick Johnson\) writes:

> On Mon, 28 Aug 2006, Alan Cox wrote:
>
>> Ar Llu, 2006-08-28 am 08:17 -0400, ysgrifennodd linux-os (Dick Johnson):
>>> On Sat, 26 Aug 2006 linux@horizon.com wrote:
>>>
>>>>> Or we could just add a standardised extra set of speed ioctls, but then
>>>>> we need to decide what occurs if I set the speed and then issue a
>>>>> termios call - does it override or not.
>>>>
>>>> Actually, we're not QUITE out of bits.  CBAUDEX | B0 is not taken.
>>>
>>> B0 is not a bit (there are no bits in 0). It won't work.
>>
>> Well that is how it is implemented and everyone else seems happy. If it
>> violates your personal laws of physics you'll just have to cope.
>
> It has nothing to do with 'personal laws of physics'. On all recent
> implementations, B0 is 0, i.e., the absence of any bits set. Therefore,
> there is no observable difference between CBAUDEX and CBAUDEX | B0,
> as shown above. Therefore, as I stated, it won't work.

What baud rate does your system define CBAUDEX | B0 to be?  On my
AMD64 machine, both the x86-64 and i386 asm/termbits.h files skip
CBAUDEX -- B38400 is 0000017 and B57600 is 0010001 (CBAUDEX | B50).
The headers do not define any baud rate between those two, either by
rate or by c_cflag value.

Michael Poole