On Wed, Jan 28, 2015 at 05:58:54PM +0000, Timur Tabi wrote:
On Wed, Jan 14, 2015 at 9:04 AM, Hanjun Guo hanjun.guo@linaro.org wrote:
From: Al Stone al.stone@linaro.org
Introduce one early parameters "off" and "force" for "acpi", acpi=off will be the default behavior for ARM64, so introduce acpi=force to enable ACPI on ARM64.
Disable ACPI before early parameters parsed, and enable it to pass "acpi=force" if people want use ACPI on ARM64. This ensures DT be the prefer one if ACPI table and DT both are provided at this moment.
What is the reason to assume that DT is preferred over ACPI? I would have thought that if ACPI is present, then it means we're on an ARM64 server platform, and therefore it should be used. It seems silly to require acpi=force on every ARM64 server platform.
I'm against requiring acpi=force when *only* ACPI tables are present (I don't like a command line argument to become firmware-kernel ABI), but otherwise DT takes precedence (it was the first supported booting method on arm64 and currently it is more mature and feature-rich than ACPI on arm64).