Re: FSL serial 166550 errata broken?

On Mon, 2017-09-25 at 17:26 +0000, York Sun wrote:

On 09/25/2017 09:55 AM, Joakim Tjernlund wrote:

quoted

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.
=20
Looking inte to driver/CPU there is an errtum(A-004737) w.r.t BREAK han=

dling

quoted

and I can see we are hitting the irq function fsl8250_handle_irq() adde=

d

quoted

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 wh=

y.

quoted

Any pointers?
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Jocke,
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Did you mean MPC8321?
=20
I personally don't have experience debugging this erratum. Have you=20
tried to contact the patch author Paul Gortmaker to see how he managed=20
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