Re: Re: [PATCH] PNPACPI: fix types when decoding ACPI resources [resend]

[Shaohua Li <shaohua.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Wed, 2005-08-03 at 09:20 -0600, Bjorn Helgaas wrote:
> On Tuesday 02 August 2005 7:01 pm, Shaohua Li wrote:
> > On Tue, 2005-08-02 at 09:55 -0600, Bjorn Helgaas wrote:
> > > Any objections to the patch below?  I posted it last Wednesday,
> > > but haven't heard anything.  Once we have this fix, 8250_pnp
> > > should have sufficient functionality that we can get rid of
> > > 8250_acpi.
> > > 
> > > Use types that match the ACPI resource structures.  Previously
> > > the u64 value from an RSTYPE_ADDRESS64 was passed as an int,
> > > which corrupts the value.
> > > 
> > > This is one of the things that prevents 8250_pnp from working
> > > on HP ia64 boxes.  After 8250_pnp works, we will be able to
> > > remove 8250_acpi.c.
> > We might always use 'unsigned long'.
> 
> Do you have a reason for preferring 'unsigned long' over the
> exact types used in the ACPI resource structures?  I thought
> it was useful to use the exact types, because then whatever
> conversion needs to happen is all in one place.
> 
> In the existing code, there's implicit conversion when you
> call "pnpacpi_parse_allocated_memresource(..., int mem, int len)"
> and pass u64 values as "mem" and "len".  You have to look both
> at the call site and the called code.  And gcc doesn't even
> complain about this truncation.
> 
> But I guess it doesn't matter much either way.
Either is ok to me.

> 
> > Did you have plan to remove other 
> > legacy acpi drivers?
> 
> No, I didn't -- which ones are you thinking about?  Looking at
> the callers of acpi_bus_register_driver(), I see:
> 
> 	arch/ia64/hp/common/sba_iommu.c
> 		Probably can't be converted because it needs the
> 		ACPI handle to extract a vendor-specific data
> 		item from _CRS.
> 
> 	drivers/char/hpet.c
> 		This probably should be converted to PNP.  I'll
> 		look into doing this.
Great! After then we could push the ACPIPNP hotplug staff.

Thanks,
Shaohua



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