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

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

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/Console/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