Messages in this thread | | | Date | Sun, 04 Jan 2015 17:39:24 +0800 | From | Hanjun Guo <> | Subject | Re: [PATCH v5 18/18] Documentation: ACPI for ARM64 |
| |
On 2014年12月25日 01:18, Catalin Marinas wrote: [...] > > In addition to the above and _DSD requirements/banning, I would also add > some clear statements around: > > _OSC: only global/published capabilities are allowed. For > device-specific _OSC we need a process or maybe we can ban them entirely > and rely on _DSD once we clarify the process. > > _OSI: firmware must not check for certain _OSI strings. Here I'm not > sure what we would have to do for ARM Linux. Reporting "Windows" does > not make any sense but not reporting anything can, as Matthew Garrett > pointed out, can be interpreted by firmware as "Linux". In addition to > any statements in this document, I suggest you patch > drivers/acpi/acpica/utosi.c accordingly, maybe report "Linux" for ARM > and print a kernel warning so that we notice earlier. > > ACPI_OS_NAME: this is globally defined as "Microsoft Windows NT". It > doesn't make much sense in the ARM context. Could we change it to > "Linux" when CONFIG_ARM64?
We will work on this both on ASWG and linux ACPI driver side, as Dong and Charles pointed out, _OSI things can be solved in ACPI spec, when that is done, we can modify the kernel driver to fix the problems above.
> > Compatibility with older kernels: ACPI firmware must work, even though > not fully optimal, with the earliest kernel version implementing the > targeted ACPI spec. There may be a need for new drivers but otherwise > adding things like CPU power management should not break older kernel > versions. In addition, the ACPI firmware must also work with the latest > kernel version.
It should be, and I think that's why we need ACPI (or DT) here :)
Thanks Hanjun
| |