On Wednesday 23 September 2015 10:15:42 Sudeep Holla wrote: > On 15/09/15 09:34, Viresh Kumar wrote: > > global_lock is defined as an unsigned long and accessing only its lower > > 32 bits from sysfs is incorrect, as we need to consider other 32 bits > > for big endian 64 bit systems. > > > > Fix that by making global_lock an u32 instead. > > > > Cc: <stable@xxxxxxxxxxxxxxx> # v4.1+ > > Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> > > > > --- > > Its marked just for # v4.1+, because arm64 has the first 64 big-endian > > platform with ACPI. And ACPI support for that is mainlined recently > > only (Arnd Bergmann). > > > > Just to clarify, we don't support big-endian with ACPI on ARM64. > We mandate use of EFI for ACPI on ARM64 and EFI spec mandates only > little endian. > EFI doesn't care what endianess the kernel has, as long as the data structures are interpreted in the same way that the firmware defines them, and I thought that at least UEFI on ARM64 with big-endian is working in principle (if not, that is a bug that should be fixed). If ACPI is broken with big-endian kernels, we should probably add a Kconfig statement to forbid it, like this: diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 5d1015c26ff4..06cacc13e3d2 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -6,6 +6,7 @@ menuconfig ACPI bool "ACPI (Advanced Configuration and Power Interface) Support" depends on !IA64_HP_SIM depends on IA64 || X86 || (ARM64 && EXPERT) + depends on !ARM64 || !CPU_BIG_ENDIAN || BROKEN depends on PCI select PNP default y Arnd -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html