Re: Timeout broken with serial port

[Lennart Sorensen]

On Mon, Sep 05, 2011 at 09:40:42PM +0200, Michal Suchanek wrote:
> I did not have the cable connected at all at the other end. Connecting
> it to my notebook resolves the problem.
> 
> Still it is definitely a bug in Grub that it interprets noise as keypresses.
> 
> Is there not DTR line?
> 
> If every switch with serial console failed to boot when there is
> nothing connected to it there would be no internet. This is not how a
> serial enabled device should behave.

If the UART (not grub) interprets noise as valid data, then it will pass
that to grub which legitimately sees that as keypresses.

Not a bug in software, just bad hardware.

DTR is used for modems and such, generally not for consoles, and besides
who is the terminal?  The serial port on many devices can be the terminal
if you connect it to a modem, but might just as well be the client device
connected to some other terminal (like when used as the grub interface).

-- 
Len Sorensen