trips over often. Specifically, in these chipsets DMA transfers that
cross a page boundary result in data corruption. The workaround is to
not allow any DMA transfers for non-static DMA maps (i.e. "real"
transfers as opposed to work areas allocated with bus_dmamem_alloc()) to
cross a page in a single S/G element. This behavior is enabled by
setting 'busdma_pyxis_bug' to 1.
- Add a new tunable 'machdep.busdma_pyxis_bug' that can be used to enable
the workaround from the loader. This can be used to enable it on
chipsets where we don't automatically enable it.
- Auto-enable the workaround for buggy PYXIS 1 chipsets supported via
cia(4).
PR: alpha/75317
04328504a1