Re: 2.0.30 floppy problem

Sam Ockman (
Mon, 9 Jun 1997 12:28:43 +0000

Just ran into this problem myself, searched my archives of this list and
found this message. Has there been any work on this in the last two
months? Is it fixed on some kernel vers? Or is it close to being fixed?

(I found it with 2.0.30.)

Also if I boot with floppy=nodma, does that only effect the speed of
floppy access, or does it have other effects?


Message from Alain Knaff ( on 4-14-97:
> >I got a message "floppy1 unable to allocate DMA memory" I had tried to
> >mount and "ls" an msdos floppy. I was in another virtual console when I
> >received the message. There has been a lot of discussion recently on
> >floppy drivers so maybe this problem has already been solved.
> >
> > Donald Harter Jr.
> >
> This problem is well known, but unfortunately there is no clean fix
> for it yet :-( The source of the problem is that only memory below
> 16M is suitable for DMA. The way how memory allocation works is that
> the memory manager first searches for suitable memory which is already
> free, and if none is found, it tries to free some more by swapping or
> tossing away buffers. Unfortunately, the last part of the algorithm
> (freeing more memory) doesn't have any knowledge of the _kind_ of
> memory requested. Hence this part will say "there is plenty of memory
> available", but all that memory will be above 16M. Thus the upper
> layer will fail because it still can't find any suitable memory.
> One workaround for this problem is to boot with floppy=nodma.

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