Subject: Re: another question about bus_space_map
To: None <tech-kern@NetBSD.ORG>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 02/04/1997 14:23:47
>> Should a probe routine unmap everything and let the attach routine
>> map it back in?
> yes. there should be no permanent allocations or initializations
> done in the match/probe routine, EVER.
I've seen this said about four times. I don't think I've ever seen it
explained _why_. I can't see any harm in, for example,
static int table_set_up = 0;
static unsigned int *table;
static void maybe_set_up_table(void)
{
if (table_set_up) return;
...allocate *table and load it...
table_set_up = 1;
}
xxx_match() {
maybe_set_up_table();
...check something on the bus using table[]...
}
Yet this is clearly forbidden by the dictum in question. So, what am I
missing?
der Mouse
mouse@rodents.montreal.qc.ca
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