Re: [MdeModulePkg/TerminalDxe] Why do we delay 2s for ESC being pressed?

[Gerd Hoffmann <kraxel@redhat.com>]

On Wed, Nov 08, 2017 at 04:44:37PM +0800, Heyi Guo wrote:
> 
> 
> 在 11/8/2017 4:34 PM, Ni, Ruiyu 写道:
> > No.
> > Even a terminal tool can recognize F10, it still needs to translate it into "ESC [ V"
> > and send the three bytes to firmware.
> Got it. But the 2 seconds timeout is not for this situation, right? If
> terminal tool could translate and send the key sequence, I think it can
> complete 3 bytes transfer in a very short time, isn't it? E.g. 9600 baud / 8
> = 1200 Bytes/s (ignore control bits).
> 
> So 2 seconds timeout is still for user to enter the sequence "ESC [ V"
> manually?

No.  Alot of software has this kind of delay because it is recommended
in some classic unix documentation to avoid mis-interpreting incomplete
terminal control sequences coming from slow terminals.

Where a "slow terminal" which actually would need such a long delay is a
physical terminal from the 70ies of the last century, or a virtual
terminal hooked up over a *really* slow network connection.

Reducing the delay from 2 seconds to roughly 0.2 seconds should be
pretty safe, things are not that slow any more these days :)

HTH,
  Gerd