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

[Heyi Guo <heyi.guo@linaro.org>]

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?

Thanks,

Heyi

>
> Thanks/Ray
>
>> -----Original Message-----
>> From: Heyi Guo [mailto:heyi.guo@linaro.org]
>> Sent: Wednesday, November 8, 2017 4:31 PM
>> To: Ni, Ruiyu <ruiyu.ni@intel.com>; Zeng, Star <star.zeng@intel.com>; edk2-
>> devel@lists.01.org
>> Cc: Dong, Eric <eric.dong@intel.com>
>> Subject: Re: [MdeModulePkg/TerminalDxe] Why do we delay 2s for ESC
>> being pressed?
>>
>>
>>
>> 在 11/8/2017 3:55 PM, Ni, Ruiyu 写道:
>>> Heyi,
>>>
>>> If you check the comments below in TerminalConIn.c:
>>>
>> https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Universal
>> /C
>>> onsole/TerminalDxe/TerminalConIn.c#L1319
>>>
>>> TerminalDxe driver needs to determine whether user wants to press ESC
>>> alone, or press "ESC [ V" for F10 (PCANSI terminal).
>> Do you mean F10 is not directly supported on some terminal tools so that we
>> need to press 3 keys "ESC [ V" quickly and continuously to emulate F10?
>>
>> Thanks,
>>
>> Heyi
>>> So a 2 second timeout is added to wait additional keys.
>>>
>>> Thanks/Ray
>>>
>>>> -----Original Message-----
>>>> From: Zeng, Star
>>>> Sent: Wednesday, November 8, 2017 3:25 PM
>>>> To: Heyi Guo <heyi.guo@linaro.org>; edk2-devel@lists.01.org
>>>> Cc: Ni, Ruiyu <ruiyu.ni@intel.com>; Dong, Eric <eric.dong@intel.com>;
>>>> Zeng, Star <star.zeng@intel.com>
>>>> Subject: RE: [MdeModulePkg/TerminalDxe] Why do we delay 2s for ESC
>>>> being pressed?
>>>>
>>>> Cc Terminal expert Ray to see if any comments on this.
>>>>
>>>>
>>>> Thanks,
>>>> Star
>>>> -----Original Message-----
>>>> From: Heyi Guo [mailto:heyi.guo@linaro.org]
>>>> Sent: Wednesday, November 8, 2017 3:04 PM
>>>> To: edk2-devel@lists.01.org
>>>> Cc: Zeng, Star <star.zeng@intel.com>; Dong, Eric
>>>> <eric.dong@intel.com>
>>>> Subject: [MdeModulePkg/TerminalDxe] Why do we delay 2s for ESC
>> being
>>>> pressed?
>>>>
>>>> Hi folks,
>>>>
>>>> We found ESC key responded fairly slow on serial port terminal, and
>>>> we think it might be caused by the code in UnicodeToEfiKey in
>> TerminalConIn.c:
>>>>        if (UnicodeChar == ESC) {
>>>>          TerminalDevice->InputState = INPUT_STATE_ESC;
>>>>        }
>>>>
>>>>        if (UnicodeChar == CSI) {
>>>>          TerminalDevice->InputState = INPUT_STATE_CSI;
>>>>        }
>>>>
>>>>        if (TerminalDevice->InputState != INPUT_STATE_DEFAULT) {
>>>>          Status = gBS->SetTimer(
>>>>                          TerminalDevice->TwoSecondTimeOut,
>>>>                          TimerRelative,
>>>>                          (UINT64)20000000
>>>>                          );
>>>>          ASSERT_EFI_ERROR (Status);
>>>>          continue;
>>>>        }
>>>>
>>>> It seems we intentionally add 2 seconds delay for ESC key press. This
>>>> provides not so good user experience when we press ESC to exit or
>>>> cancel some operation.
>>>>
>>>> We tried reducing this timeout value to 1 second, then the experience
>>>> improved much and we didn't find any issue introduced.
>>>>
>>>> What's the reason for this timeout value and is there any improvement?
>>>>
>>>> Thanks and regards,
>>>>
>>>> Heyi