Re: [PATCH V2 2/4] ACPI/scan: Clean up acpi_check_dma

From: Suravee Suthikulpanit
Date: Tue Aug 25 2015 - 22:00:51 EST

Hi Rafael,

On 8/26/15 06:48, Rafael J. Wysocki wrote:

On Wednesday, August 26, 2015 12:33:27 AM Suravee Suthikulpanit wrote:
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index b9657af..55cf916 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -168,7 +168,7 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
struct list_head *physnode_list;
unsigned int node_id;
int retval = -EINVAL;
- bool coherent;
+ int coherent;

enum, anyone? With clearly defined values?

Originally I had defined

enum acpi_dma_coherency {

Although, this would need to be defined in the include/linux/acpi.h, and will be used also for #ifndef CONFIG_ACPI code to return errors. I was not sure if this would be too much. If this is preferred, I'll add this back in.

if (has_acpi_companion(dev)) {
if (acpi_dev) {
@@ -225,7 +225,8 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
if (!has_acpi_companion(dev))
ACPI_COMPANION_SET(dev, acpi_dev);

- if (acpi_check_dma(acpi_dev, &coherent))
+ coherent = acpi_check_dma_coherency(acpi_dev);
+ if (coherent != -1)

Like here I'm not sure why -1 is special?

It's just another value to communicate that DMA is not supported. :)


arch_setup_dma_ops(dev, 0, 0, NULL, coherent);

acpi_physnode_link_name(physical_node_name, node_id);


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