Re: 2.5.4 sound module problem

From: Alan (alan@clueserver.org)
Date: Wed Feb 13 2002 - 00:18:17 EST


On Tuesday 12 February 2002 21:03, John Weber wrote:
> Alan wrote:
> > On Tuesday 12 February 2002 19:51, Albert Cranford wrote:
> >>Not sure if this was the same message I received. but here
> >>is the patch I used to get around my sound problem in
> >>2.5.4.
> >
> > Are you sure this is correct? include/asm/io.h seems to indicate that
> > i/o addresses for PCI may not map correctly. The sound card I am using
> > is PCI, not ISA.
>
> You should not use isa_virt_to_bus. IIRC someone on this list worried
> about this exact thing happening.

Glad I checked before adding the patch... ]:>

> > Documentation/DMA-mapping.txt says that virt_to_bus is completly
> > depreciated and nothing should be using it. Well, grepping the kernel
> > source shows that quite a bit still uses it.
>
> This is on the kernel janitor TODO, and we (janitors) will be tackling
> this shortly. But your instinct is right, virt_to_bus shouldn't be
> everywhere.

IMHO 2.5.4 is pretty broken until that gets fixed. the list is pretty long
as well.

> > What it looks like, on first glance, is that virt_to_bus was changed for
> > pci devices to give this error message. (Since that symbol goes
> > nowhere.) That effects a number of things, not just sound. (A whole
> > bunch of cardbus drivers I would guess...)
>
> This is correct. It has been a policy to use pci_alloc_consistent
> instead of kmalloc/getfreepages and virt_to_bus, 2.5 is enforcing it now.

By breaking sound (in dmabuf and sound modules), cardbus (lots of places),
and who knows what else.

"grep -r virt_to_bus | less" shows jut how bad it is going to be...

> It is boring work to change this in many drivers, but I don't know any
> better so I think it quite fun to go in and help :). I'll start sending
> patches to the relevant maintainers shortly.

Thanks.

It just makes me wonder if anyone actually compiled this and ran it before it
was released.

Back to 2.4.x land for a while i guess... (At least on this machine.)

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Feb 15 2002 - 21:00:52 EST