On Thu, Jan 09, 2014 at 09:20:23PM +0000, Al Stone wrote: > On 01/09/2014 10:38 AM, Catalin Marinas wrote: > > On 8 January 2014 12:46, Arnd Bergmann <arnd@xxxxxxxx> wrote: > >> On Wednesday 08 January 2014, al.stone@xxxxxxxxxx wrote: > >>> Even though support for X86 in hardware reduced mode is possible, it > >>> is NOT enabled. Extensive effort has gone into the Linux kernel so that > >>> there is a single kernel image than can run on all x86 hardware; the kernel > >>> changes run-time behavior to adapt to the hardware being used. This is not > >>> currently possible with the existing ACPICA infrastructure but only presents > >>> a problem on achitectures supporting both hardware-reduced and legacy modes > >>> of ACPI -- i.e., on x86 only. > >> > >> Not sure about the logic here: While it's certainly possible to build a kernel > >> that runs on all x86 machines, it's also possible to build one that only > >> runs on some of them when some basic options are turned off. I don't see > >> any difference between that and what we have on ARM64 or the multiplatform > >> subset of ARM32. > > > > Would we ever need !CONFIG_ACPI_REDUCED_HARDWARE_ONLY on ARM or ARM64? > > If not, we could even make this always on for these archs. > > > > Not that I know of -- and I would hope not. This mode is so much > more straightforward that it makes no sense to me to do anything > but reduced HW if you have the choice. Thanks for clarifying. > I assume you were thinking of something like this in the arch Kconfig > file: > > config ARM64 > .... > select ACPI_REDUCED_HARDWARE_ONLY if ACPI > ... > > But, do let me know if you had something else in mind. I think it does > make sense to add so I'll put this in the next version. The change makes sense but I think it should come with the patches for ACPI support on arm64 rather than your hw-reduced patches. -- Catalin -- 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
