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Subject: Re: Interesting AML bug... recommended workaround?
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Date: Mon, 02 Oct 2000 14:58:39 +0900
From: Mitsuru IWASAKI <iwasaki@jp.FreeBSD.org>
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> Here's what seems to be an interesting AML or AML parser bug.
> 
> 	OperationRegion(PSRG, SystemMemory, 0x0410, 0x1)
> 	Field(PSRG, DWordAcc, NoLock, Preserve) {
> 		,	2,
> 		PS2E,	1
> 	}
> 
> The field is marked for 32-bit access, but the region is only 1 byte 
> wide.  What's the correct thing to do here?  Expand the region to 
> accomodate the field's access requirements?  Constrain the access size of 
> the field to that of the region?

I thought read 32-bit, update target bits, write back whole 32-bit for
updating.  For reading value, read 32-bit and shift & mask bits as well.
I hope I could understand description in Spec 15.2.3.3.1.9; "If desired,
AccessType can be used to force minimum access width."

Thanks


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