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ACPI: Honor ACPI _CCA attribute setting

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ACPI configurations can now mark devices as noncoherent,
support that choice.

NOTE: This is required to support USB on ARM Juno Development Board.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Jeremy Linton 2015-10-28 15:50:46 -07:00 committed by Rafael J. Wysocki
parent 5293fea28c
commit d764c21c7b
1 changed files with 3 additions and 2 deletions
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5
include/acpi/acpi_bus.h
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@ -407,7 +407,7 @@ static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
* case 1. Do not support and disable DMA.
* case 2. Support but rely on arch-specific cache maintenance for
* non-coherence DMA operations.
* Currently, we implement case 1 above.
* Currently, we implement case 2 above.
*
* For the case when _CCA is missing (i.e. cca_seen=0) and
* platform specifies ACPI_CCA_REQUIRED, we do not support DMA,
@ -415,7 +415,8 @@ static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)
*
* See acpi_init_coherency() for more info.
*/
if (adev->flags.coherent_dma) {
if (adev->flags.coherent_dma ||
(adev->flags.cca_seen && IS_ENABLED(CONFIG_ARM64))) {
ret = true;
if (coherent)
*coherent = adev->flags.coherent_dma;