Problems with serial interrupts with IPMI 2.0 SoL

Jeremy Fitzhardinge
2009-12-10T21:45:51Z

Hi,

I'm using a system with an embedded IPMI 2.0 BMC which provides SoL
(Supermicro X8SIL-F). This works fine under Linux (fully interrupt
driven), but fails for Xen as it appears to not be sending interrupts;
it works OK if I set the driver to polling mode.

I'm assuming the Xen is tickling some bug in the emulated 16550. The
Linux driver has a couple of pieces of code to explicitly work around
bugs in the Intel AMT SoL implementation, but I don't think they're
coming into play here (because there are no Intel SoL PCI devices on
this system to trigger the NO_TXEN_TEST flag).

I'm wondering if you have any pointers or suggestions about more subtle
problems?

Thanks,
J