Re: 2.5.4 sound module problem

From: John Weber (john.weber@linuxhq.com)
Date: Wed Feb 13 2002 - 00:03:01 EST


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.

> 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.

> 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.

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.

By the way, anyone know who the maintainer is for the persistent DMA
buffer code?

-- 
(o- j o h n   e   w e b e r
//\  http://www.linuxhq.com/people/weber/
v_/_ john.weber@linuxhq.com

- 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