How to detect serial buffer overruns

How to detect serial buffer overruns

[Corbin]

Hello,

Most of the documentation that I find to detect buffer overruns says
to use the TIOCGICOUNT ioctl along with serial_icounter_struct. It
appears, however,  that the buf_overrun field in this struct is not
updated in the 8250 driver. I confirmed this by writing a lot of data
to my computer's built-in serial port at 115200 baud and then doing a
read, which resulted in only receiving 69376 bytes back. It appears
the tty flip buffers begin to overflow at 69376 bytes, but again, the
buf_overrun field in the serial_icounter_struct shows no change after
calling the TIOCGICOUNT ioctl. I am able to get other information from
the ioctl just fine, such as parity, break, and framing errors. I went
through several of the drivers in /drivers/tty/serial and
drivers/usb/serial and it looks like my problem stems from that fact
that there aren't really any serial drivers that make use of
buf_overrun, including the 8250 driver which my port is using.

So, my question is, what is the recommended way to detect buffer overruns?

Thanks,
Corbin Atkinson
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