From d764c21c7b1aa5ce982eaa8400517d8004d30267 Mon Sep 17 00:00:00 2001 From: Jeremy Linton Date: Wed, 28 Oct 2015 15:50:46 -0700 Subject: ACPI: Honor ACPI _CCA attribute setting 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 Signed-off-by: Suravee Suthikulpanit Acked-by: Bjorn Helgaas Reviewed-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki --- include/acpi/acpi_bus.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/acpi/acpi_bus.h') diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index e234725eadc7..8df990520304 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -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; -- cgit