On Wed, Mar 1, 2017 at 9:38 PM, Moore, Robert <robert.moore@xxxxxxxxx> wrote: > Sorry if I've missed any of this conversation, but I have a couple of thoughts: > > 1) It might be sufficient to just compare the incoming table header (36 bytes). The header contains both the table length and the checksum -- as well as the OEM ID and OEM version. I take it that the XSDT pointers to the duplicate tables are different. > > 2) As far as comparing every incoming SSDT byte-for-byte against all previously loaded SSDTs, I have to think "what about the boot time?". Especially since SSDTs are increasing in both size and number (See example from a real machine below). > > > ACPI: RSDP 0x0000000000492954 000024 (v02 Intel ) > ACPI: XSDT 0x000000000068C938 0000B4 (v00 Intel AcpiExec 00001001 INTL 20170224) > ACPI: FACP 0x0000000000492978 000114 (v05 Intel AcpiExec 00001001 INTL 20170224) > ACPI: DSDT 0x0000000000690048 022FD6 (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: FACS 0x0000000000492AB0 000040 > ACPI: SSDT 0x00000000006B3028 0004B7 (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x000000000068D940 000B49 (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006B34E8 0004A3 (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006B3998 000E58 (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006B47F8 00037F (v02 PmRef Cpu0Cst 00003001 INTL 20121220) > ACPI: SSDT 0x000000000068E498 000660 (v02 PmRef Cpu0Ist 00003000 INTL 20121220) > ACPI: SSDT 0x00000000006B4B80 0005AA (v02 PmRef ApIst 00003000 INTL 20121220) > ACPI: SSDT 0x000000000068EB00 000119 (v02 PmRef ApCst 00003000 INTL 20121220) > ACPI: SSDT 0x000000000068EC28 00004B (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006B5138 0052EE (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006BA430 002C4A (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006BD088 0004C8 (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x000000000068EC80 0002D4 (v01 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006BD558 002BAE (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006C0110 00019A (v02 LENOVO CB-01 00000001 ACPI 00040000) > ACPI: SSDT 0x00000000006C02B8 0006DC (v02 LENOVO CB-01 00000001 ACPI 00040000) > Right. Whatever allows us to make a "we've loaded this table already, skip it" decision without comparing byte-for-byte, please. Thanks, Rafael -- 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
