FreeCalypso > hg > freecalypso-tools
view old/linux-2.6.37.6-ftdi_sio.c.patch @ 407:19e5a3e2f9c0
fcup-settime: moved time() retrieval a little closer to the output
A fundamental problem with all simple time transfer tools is that there is
always some delay between the time retrieval on the source system and that
transmitted time being set on the destination, and the resulting time
on the destination system is off by that delay amount. This delay cannot
be fully eliminated when working in a simple environment like ours,
but we should make our best effort to minimize it. In the present case,
moving the atinterf_init() call before the time() retrieval should make
a teensy-tiny improvement.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Sat, 11 Aug 2018 21:52:17 +0000 |
| parents | 40f44aa49dd0 |
| children |
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--- ftdi_sio.c.orig 2011-03-27 11:01:41.000000000 -0800 +++ ftdi_sio.c 2015-10-30 13:18:40.879000032 -0800 @@ -949,7 +949,7 @@ static const unsigned char divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 }; __u32 divisor; /* divisor shifted 3 bits to the left */ - int divisor3 = base / 2 / baud; + int divisor3 = (base / 2 + baud / 2) / baud; divisor = divisor3 >> 3; divisor |= (__u32)divfrac[divisor3 & 0x7] << 14; /* Deal with special cases for highest baud rates. */ @@ -1087,6 +1087,17 @@ baud = tty_get_baud_rate(tty); dbg("%s - tty_get_baud_rate reports speed %d", __func__, baud); + /* + * FreeCalypso hack: translate non-std high + * baud rates for GSM like CP2102 does. + */ + if (baud == 230400) + baud = 203125; + else if (baud == 460800) + baud = 406250; + else if (baud == 921600) + baud = 812500; + /* 2. Observe async-compatible custom_divisor hack, update baudrate if needed */