Re: [PATCH] 8250 UART backup timer

[Alex Williamson]

On Tue, 2006-06-27 at 12:15 -0700, H. Peter Anvin wrote:
> Alex Williamson wrote:
> >    The patch below works around a minor bug found in the UART of the
> > remote management card used in many HP ia64 and parisc servers (aka the
> > Diva UARTs).  The problem is that the UART does not reassert the THRE
> > interrupt if it has been previously cleared and the IIR THRI bit is
> > re-enabled.  This can produce a very annoying failure mode when used as
> > a serial console, allowing a boot/reboot to hang indefinitely until an
> > RX interrupt kicks it into working again (ie. an unattended reboot could
> > stall). 
> 
> I have seen this same bug in soft UART IP from "a major vendor."

   If you get a chance to try, please let us know if this patch works
there too or needs any additional tweaking to make it work there.
Thanks,

	Alex

-- 
Alex Williamson                             HP Open Source & Linux Org.

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