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SubjectRE: serial driver question
Date
Guennadi Liakhovetski wrote:
> Hello all
>
> The function
> static int size_fifo(struct async_struct *info)
> {
> ...
> ends as follows:
> serial_outp(info, UART_LCR, UART_LCR_DLAB);
> serial_outp(info, UART_DLL, old_dll);
> serial_outp(info, UART_DLM, old_dlm);
>
> return count;
> }
>
> Which means, that DLAB is not re-set, and, in particular, all
> subsequent read/write operations on offsets 0 and 1 will not
> affect the data and interrupt enable registers, but the divisor
> latch register... Or is this register somehow magically restored
> elsewhere or by the hardware (say, on an interrupt)? This
> function seems to be only called for startech UARTs.

Hi Guennadi,

I'll look at it as soon as my system is up. It's morning boot-up time here.
Have a good evening.

Ed Vance

----------------------------------------------------------------
Ed Vance edv@macrolink.com
Macrolink, Inc. 1500 N. Kellogg Dr Anaheim, CA 92807
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