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@xxxxxxxxxxxxxxx [mailto:linux-acpi-owner@xxxxxxxxxxxxxxx] 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: 0x074 > * FADT V2 size: 0x084 > * FADT V3 size: 0x0F4 > * FADT V4 size: 0x0F4 > * FADT 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 :) > > Thanks > Hanjun > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
