jmmv@menta.net ("Julio M. Merino Vidal") writes:

>Thus, when the memory is very fragmented, the USB device can't
>map a single, big chunk of memory for its own uses.

Indeed. There are two issues.

Somewhen in the past the kernel started to fragment memory significantly
more. Nobody knows yet why. Fixing this won't make the problem go away
but reduces the probability.

The umass driver requires a big chunk of memory while the hardware
could live with fragmented memory. When this is fixed the problem
goes away.

N.B. the same problem exists in NetBSD-1.6.
-- 
-- 
                                Michael van Elst
Internet: mlelstv@serpens.de
                                "A potential Snark may lurk in every tree."