Re: [PATCH 1/2] arm/arm64: ACPI: Introduce CONFIG_ACPI_MUST_HAVE_CCA
From: Suravee Suthikulpanit
Date: Wed Apr 29 2015 - 10:45:01 EST
On 04/29/2015 09:42 AM, Catalin Marinas wrote:
On Wed, Apr 29, 2015 at 09:31:03AM -0500, Suravee Suthikulpanit wrote:
On 04/29/2015 09:04 AM, Catalin Marinas wrote:
On Wed, Apr 29, 2015 at 08:44:08AM -0500, Suravee Suthikulpanit wrote:
From ACPIv6 (http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf),
section 6.2.17 _CCA states that ARM platforms require ACPI _CCA object to be
specified for DMA-cabpable devices. This patch introduces ACPI_MUST_HAVE_CCA
in arm and arm64 Kconfig to specify such requirement.
Note that when _CCA is required, if it is missing in the DSDT. ACPI driver
will default to setting up devices as non-coherent.
Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
---
arch/arm/Kconfig | 1 +
arch/arm64/Kconfig | 1 +
drivers/acpi/Kconfig | 3 +++
3 files changed, 5 insertions(+)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 45df48b..2a0d036 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1,6 +1,7 @@
config ARM
bool
default y
+ select ACPI_MUST_HAVE_CCA if ACPI
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
Any plans for ACPI on 32-bit ARM?
Not that I am aware, but I could be totally wrong. The reason I am adding
this here for 32-bit ARM is because the ACPI spec mentioned this.
If you think this is not necessary until we introduce ACPI for ARM32, it can
be removed.
I think it should be removed (as long as ACPI cannot be selected on
arm32).
Ok, I'll remove that in V2.
Thanks,
Suravee
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/