Re: [Dri-devel] PPC Lockup (ati-pcigart-branch)

On Tue, 23 Jan 2001, Robert E Brose II wrote:

On Mon, 22 Jan 2001, Dan Malek wrote:

quoted

quoted

quoted

.....  I
wonder why planb works at all....

Probably because no one stumbles across the memory it is trashing?
Currently, bad_thing_will_happen = vmalloc + virt_to_bus + dma.
It could be with the right memory size, modulo addressing, memory
controller configuration, timing of the vmalloc, it just may
accidently work.  If this is the case, I would be out buying
lottery tickets........

On Mon, 22 Jan 2001, Takashi Oe wrote:

quoted

Ok, my apologies, planb doesn't use vmalloc at all these days.  So, there
is no problem of that kind.  (In the beginning, it had vmalloc with a lot
of problems as I recall now.)

How about the use of vmalloc in the video frame buffer drivers? At
one point I ran into some weird behavior with controlfb (mmap patched),
XFree4.0, planb and Xawtv (the xawtv display froze the machine). I was
not able to duplicate that in X3.3.6

The frame buffer device drivers don't use vmalloc(), except for vfb, which is a
sample driver that works on vmalloc()'ed memory instead of on real video
memory. But you're right that vfb can crash if you try to mmap() its /dev/fb*,
since it's vmalloc()'ed.

However, that doesn't matter since no one will ever really use vfb :-)

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds


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