Re: Changes to UART ns8250

Hi,

You should add:

* a loop counter, to break out after a while;
* a DELAY(1) or something.



-adrian



On 7 October 2013 12:54, Zbigniew Bodek <zbb_at_freebsd.org> wrote:

> Hello.
>
> I would like to present a patch for ns8250 serial that I would like to
> commit in the near future (if there are no objections).
>
> The patch is fixing newest DesignWare UART with busy detection.
> During frequency divisors configuration when UART is busy transferring or
> receiving data, line control register manipulation will not take effect.
> Therefore, we will not set divisor latch access bit and we will corrupt LCR
> instead of configuring divisors.
> It is necessary to wait until UART finishes all transfers to proceed with
> the configuration.
>
> This was detected on Armada XP as UART fails on this issue 100/100
> attempts.
> The patch was tested by kevlo_at_ and me and it works on our Armada XP -
> based
> systems.
>
> Please send your comment or remarks if there are any.
>
> Best regards
> Zbigniew Bodek
>
> _______________________________________________
> freebsd-current_at_freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org"
>