uart(4) 16550A FIFO latency too long

UEMURA Tetsuya t_uemura at
Mon Mar 10 17:56:20 PDT 2008

Hi there.

I have a timing sensitive sensor device connected to PC with serial
ports. In order to gather data from the device correctly, I have to set
the 16550A FIFO interrupt trigger level lower than the default

However, there's no tunable in uart(4) to set these levels manually,
so I've added some lines to uart(4) and now I've been able to set the
level via device.hints.

Please someone review the following PR. .

Thank in advance.

UEMURA Tetsuya <t_uemura at>

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