Hi,
Using size instead of version field to determine FADT version has been talked for many times. I didn't see a real case that was persuasive enough to introduce this change. Do you have real platforms for us to examine?
Thanks and best regards -Lv
From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-owner@vger.kernel.org] On Behalf Of Hanjun Guo Sent: Wednesday, May 07, 2014 4:14 PM
Hi,
I ran into some compile errors when I was prototyping the code for the proposals in ASWG, it turns out that some field in FADT is changed and "reserved4[0]" used in ACPI_FADT_V2_SIZE will cause the error.
So my question is that the length of very version of FADT is fixed, why not use a constant value for this puspose?
Here is the code:
/*
- Sizes of the various flavors of FADT. We need to look closely
- at the FADT length because the version number essentially tells
- us nothing because of many BIOS bugs where the version does not
- match the expected length. In other words, the length of the
- FADT is the bottom line as to what the version really is.
- For reference, the values below are as follows:
FADT V1 size: 0x074FADT V2 size: 0x084FADT V3 size: 0x0F4FADT V4 size: 0x0F4FADT V5 size: 0x10C*/ #define ACPI_FADT_V1_SIZE (u32) (ACPI_FADT_OFFSET (flags) + 4) #define ACPI_FADT_V2_SIZE (u32) (ACPI_FADT_OFFSET (reserved4[0]) + 3) #define ACPI_FADT_V3_SIZE (u32) (ACPI_FADT_OFFSET (sleep_control)) #define ACPI_FADT_V5_SIZE (u32) (sizeof (struct acpi_table_fadt))
Why not #define ACPI_FADT_V1_SIZE 0x074 ? Did I miss something? any clarify will be appreciated :)
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