Subject: bus_dmamem_alloc(9) question
To: None <firstname.lastname@example.org>
From: Ingolf Koch <email@example.com>
Date: 02/16/2000 22:55:23
according to bus_dma(9), the third (alignment) and fourth
(boundary) parameters of bus_dmamem_alloc() must be a
power of 2. Grepping for bus_dmamem_alloc in src/sys/dev/*/*.c
shows many calls where one of the two parameters is 0, i.e.
not a power of 2. One of the many examples is ic/cs4231.c 1.2,
While an alignment of 0 is probably harmless ("it will be
rounded up to the hardware page size"), a boundary of 0 is
not (bus_dma(9): "A boundary value less than the size of the
allocation is invalid.").
How is the value 0 handled?
Ingolf Koch ICQ#60829470 Beste Kneipe in Jena-Ost
PGP: 0x7B3B5661 213C 828E 0C92 16B5 05D0 4D5B A324 EC04