FSL serial 166550 errata broken?

[Joakim Tjernlund]

On Mon, 2017-09-25 at 17:26 +0000, York Sun wrote:
> On 09/25/2017 09:55 AM, Joakim Tjernlund wrote:
> > We got some "broken" boards(mpx8321) where UART RX is held low(BREAK)
> > There we get a few:
> >    serial8250: too much work for irq18
> > and the board freezes.
> > 
> > Looking inte to driver/CPU there is an errtum(A-004737) w.r.t BREAK handling
> > and I can see we are hitting the irq function fsl8250_handle_irq() added
> > in commit: 9deaa53ac7fa373623123aa4f18828dd62292b1a
> >   "serial: add irq handler for Freescale 16550 errata."
> > For all I can tell this workaround is broken and I cannot figure out why.
> > Any pointers?
> > 
> 
> Jocke,
> 
> Did you mean MPC8321?
> 
> I personally don't have experience debugging this erratum. Have you 
> tried to contact the patch author Paul Gortmaker to see how he managed 
> to get it work?

No, but I just found out it is u-boot related. If I use an very old u-boot it works.
Between then and now we did a massive upgrade of u-boot and now if breaks. And no,
bisect not possible due to local u-boot mods :)

Any idea what could be different? I cannot see and I have tested
what I could see/think of but now I am out of ideas.

 Jocke