mss.c pcm fix to ' attach returned 6 ' load failure for v5.x
acpi and up
Nate Lawson
nate at root.org
Sun Jul 17 04:18:13 GMT 2005
M. Warner Losh wrote:
> <the refs are wrong for this reply>
> Nate writes:
>
>>I really think the driver is broken and the API is fine for this. I
>>don't like the hack of returning a random CID for checks against the
>>HID. Drivers down the road may come to rely on this and then every BIOS
>>that has a different order for CIDs becomes a potential breakage point.
>
>
> They alredy do rely on this. When they support pnp, they call the
> ISA_PNP_PROBE routine. When they don't then your observation doesn't
> matter because the order of the IDs doesn't matter: their non-zeroness
> does.
>
>
>>Drivers should not rely on isa_get_logicalid() to determine a boolean
>>"is PNP?"
>
>
> Actually, that's the interface. We have to follow it, even if you
> think it is stupid. It is how we do things. When we don't have a
> logicalid, we return 0. When drivers don't support pnp devices, it
> uses the existance of a non-zero pnpid to know the device isn't for
> them. It has been this way since 3.0.
>
> Warner
Rather than John's addition of returning an arbitrary CID, can we return
~0 or some other obviously invalid HID so that drivers don't start
depending on the order of CIDs?
--
Nate
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