[alsa-devel] [PATCH] sound/isa: kill pnp_resource_change.

Rene Herman rene.herman at gmail.com
Thu Nov 29 18:35:45 CET 2007

On 29-11-07 17:20, Bjorn Helgaas wrote:

> On Wednesday 28 November 2007 06:10:33 pm Rene Herman wrote:

>> This removes the pnp_resource_change use from the ALSA ISAPnP drivers. In
>> 2.4 these were useful in providing an easy path to setting the resources,
>> but in 2.6 they retain function as a layering violation only.
>> This makes for a nice cleanup (-550 lines) of ALSA but moreover, ALSA is the
>> only remaining user of pnp_init_resource_table(), pnp_resource_change() and
>> pnp_manual_config_dev() (and, in fact, of "struct pnp_resource_table") in
>> the tree outide of drivers/pnp itself meaning it makes for more cleanup
>> potential inside the PnP layer.
> I think this is great and will certainly clean up the PNP interfaces.
> But are you removing functionality that people need?  I don't know
> anything about ALSA, but we have to assume that some BIOSes supply
> incorrect resource information.  If you remove all these module
> parameters, is there still a way to workaround the BIOS defects?

Yes, sure, by just echoing resource values into sysfs files as a direct 
replacement (ie, doing the same thing at the PnP layer directly) and 
possibly by adding quirks for any definite and standing issues. We already 
have a few of those in fact for SB16, AWE32 and CMI8330 chips, in 

But the expected use is just no manual settings at all, same as with say 
PCI. I've always been a little disappointed at the ISAPnP bad rep. It's a 
fully sane bus as far as the interface is concerned.

And by the way, real-life issue with sound and PnP seems to be confined to 
older laptops with an onboard Cirrus CS423x advertised through PnPBIOS/ACPI 
  and PnPBIOS/ACPI claiming the resources could not actually be changed, 
which the now removed code tried to do anyway. You were CCed on a report of 
that a while ago. Don't know if that went anywhere but if anything, this 
removal of the problematic code makes it better (probably fixes it fully in 


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