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authorJeremy Linton <jeremy.linton@arm.com>2015-10-28 15:50:46 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-11-07 01:29:21 +0100
commitd764c21c7b1aa5ce982eaa8400517d8004d30267 (patch)
treec5ead5eb59210359bc29d8d308df3ac829644f80
parent5293fea28c9355a12792c4a85c9daad612efc503 (diff)
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 <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>
-rw-r--r--include/acpi/acpi_bus.h5
1 files changed, 3 insertions, 2 deletions
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;