Hi Al, On Tue, Jun 30, 2015 at 7:29 PM, Al Stone <ahs3@xxxxxxxxxx> wrote: > On 06/30/2015 11:07 AM, Sudeep Holla wrote: >> Hi Al, >> >> On 18/06/15 23:36, Al Stone wrote: >>> In the ACPI 5.1 version of the spec, the struct for the GICC subtable >>> (struct acpi_madt_generic_interrupt) of the MADT is 76 bytes long; in >>> ACPI 6.0, the struct is 80 bytes long. But, there is only one definition >>> in ACPICA for this struct -- and that is the 6.0 version. Hence, when >>> BAD_MADT_ENTRY() compares the struct size to the length in the GICC >>> subtable, it fails if 5.1 structs are in use, and there are systems in >>> the wild that have them. >>> >>> Note that this was found in linux-next and these patches apply against >>> that tree and the arm64 kernel tree; 4.1-rc8 does not appear to have this >>> problem since it still has the 5.1 struct definition. >>> >>> Even though there is precendent in ia64 code for ignoring the changes in >>> size, this patch set instead tries to verify correctness. The first patch >>> in the set adds macros for easily using the ACPI spec version. The second >>> patch adds the BAD_MADT_GICC_ENTRY() macro that uses the version macros to >>> check the GICC subtable only, accounting for the difference in specification >>> versions that are possible. The final patch replaces BAD_MADT_ENTRY usage >>> with the BAD_MADT_GICC_ENTRY macro in arm64 code, which is currently the >>> only architecture affected. The BAD_MADT_ENTRY() will continue to work as >>> is for all other MADT subtables. >>> >> >> We need to get this series or a patch to remove the check(similar to >> ia64) based on what Rafael prefers. Without that, platforms using ACPI >> on ARM64 fails to boot with latest mainline. This blocks any testing on >> ARM64/ACPI systems. >> >> Regards, >> Sudeep > > I have not received any other feedback than some Reviewed-bys from > Hanjun and an ACK from Will for the arm64 patch. > > And absolutely agreed: this is a blocker for arm64/ACPI, starting with > the ACPICA 20150515 patches which appear to have gone in with 4.2-rc1. > > Rafael? Ping? I overlooked the fact that this was needed to fix a recent regression, sorry about that. Actually, if your patch fixes an error introduced by a specific commit, it is good to use the Fixes: tag to indicate that. Which I still would like to do, so which commit is fixed by this? > Do we need these to go through your tree or the arm64 > tree? Without this series (or an ia64-like solution), we have ACPI > systems in the field that cannot boot. I'm not quite sure why the definition of BAD_MADT_GICC_ENTRY has to go into include/linux/acpi.h. Why is it necessary in there? 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
