ACPI: Honor ACPI _CCA attribute setting (d764c21c) · Commits · 戴 / test

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>

include/acpi/acpi_bus.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -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;

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