On Tue, Jul 31, 2018 at 06:11:32PM +0200, Maxime Villard wrote: > It is really strange. The fact that we receive exception 0x10 seems to > indicate that there is a problem somewhere related to the pin/irq > initialization, but I don't really see how the delay could fix that. Or > maybe the printfs do something more than just adding delay, I don't > really know. > > Does that ring a bell to someone? Running out of ideas... Phew, I liked > these machines...
Supposing it is actually a PCI exception: Maybe the delay gives the target of the `outl` enough time to finish some initialization. Maybe the target doesn't respond to PCI I/O-space writes until the initialization has finished, and the write is retried until some retry limit is exceeded. It's also possible that the PCI I/O-space access generated by the `outl` is flushing a posted PCI memory-space access, and it's the memory-space access that causes a PCI exception. Can you look at the PCI error state on the bridges and devices in the system? I don't remember if `ddb` will show that, but it may not be hard to add. The error state may lead you quickly to the precise device that's generating the exception. Dave -- David Young [email protected] Urbana, IL (217) 721-9981
