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
