Heyi,
The function TerminalConInTimerHandler () computes a timeout based on the baud
rate, data bits, and stop bits
//
// According to BAUD rate to calculate the timeout value.
//
SerialInTimeOut = (1 + Mode->DataBits + Mode->StopBits) * 2 * 1000000 /
(UINTN) Mode->BaudRate;
The #define is used to set the initial periodic timer rate before the rest of
the information to compute a timeout is known.
Are you observing an issue?
Mike
>-----Original Message-----
>From: edk2-devel [mailto:[email protected]] On Behalf Of Heyi
>Guo
>Sent: Monday, November 09, 2015 1:48 AM
>To: [email protected]
>Cc: Tian, Feng
>Subject: [edk2] [RFC] Adaptively set serial terminal input polling interval
>
>Hi All,
>
>In MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf, the
>polling interval is fixed by macro:
>
>#define KEYBOARD_TIMER_INTERVAL 200000 // 0.02s
>
>However, this may cause fast input to be truncated on some platform. For
>example, we have a serial console with below features:
>1. Baud rate: 115200
>2. FIFO depth of UART device: 32
>
>If we want to capture all input, we need to poll with the interval of 32
>/ (115200 / (8 + 1 + 1)) = 2.8 ms, 8 + 1 + 1 for data bits + start bit +
>stop bit.
>
>So, I suppose to use a PCD to set the interval per platform, or
>calculate from serial IO protocol IO Mode, which contains FIFO depth and
>data bits, etc, and we can use 200000 as the maximum for compatibility,
>or default value when fifo depth is 0.
>
>Please let me know your comments.
>
>Thanks.
>
>Heyi
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