Disable FIFO on UART
Miguel Barbosa Gonçalves
m at mbg.pt
Sun May 5 12:00:04 UTC 2013
Back in FreeBSD 7 there was a flag to disable the FIFO on the sio
device driver. From
Meaning of flags:
0x00001 shared IRQs
0x00002 disable FIFO
0x00004 no AST/4 compatible IRQ control register
0x00008 recover sooner from lost output interrupts
0x00010 device is potential system console
0x00020 device is forced to become system console
0x00040 device is reserved for low-level IO (e.g. for remote kernel debugging)
0x00080 use this port for remote kernel debugging
0x0??00 minor number of master port
0x10000 PPS timestamping on CTS instead of DCD
0x20000 device is assumed to use a 16650A-type (extended FIFO) chip
Now with FreeBSD 8 which uses the UART device driver there's no option for that.
I am looking to reduce the jitter I am getting on the serial port when
connecting a GPS to the server.
Can anyone help?
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