hi,

just tried to boot a currend kernel w/ mp-support compiled from
sources as of 2 days or so ago on my ss20. during fsck the
machine hangs at some point. L1-a still gets to ddb, so here's the
trace:

_kbd_rxint
_zsc_intr_hard
_zshard
_sparc_interrupt44c
_lsi64854_setup
_iommu_dmamap_unload
_isp_sbus_dmateardown
_isp_intr
_sparc_interrupt44c
_tsleep
_extent_alloc_subregion1
_iommu_dmamap_load
_lsi64854_setup
_esp_dma_setup
_ncr53c9x_intr
_sparc_interrupt44c
_mi_switch
_tsleep
_physio
_sdread
_spec_read
_ufsspec_read
_vn_read
_dofileread
_sys_read
_syscall
syscall

hm, seems that the onboard esp and the sbus isp "don't like" each
other doing dma?
this hang is reproducible at will: just fsck partitions on a disk at
the esp and another one at the isp in parallel...

can i do something to help debugging this?

-kurt