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

From: Rafael J. Wysocki
Date: Tue Aug 25 2015 - 19:20:43 EST


On Wednesday, August 26, 2015 12:33:27 AM Suravee Suthikulpanit wrote:
> The original name of acpi_check_dma() function does not clearly tell what
> exactly it is checking. Also, returning two boolean values (one to indicate
> device is DMA capability, and the other to inidicate device coherency
> attribute) can be confusing.
>
> So, in order to simplify the function, this patch renames acpi_check_dma()
> to acpi_check_dma_coherency() to clearly indicate the purpose of this
> function, and only returns an integer where -1 means DMA not supported,
> 1 means coherent DMA, and 0 means non-coherent DMA.
>
> Also, this patch moves the function into drivers/acpi/scan.c since
> it is easier to follow the logic in the acpi_init_coherency() in the
> same file here.
>
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> CC: Catalin Marinas <catalin.marinas@xxxxxxx>
> CC: Rob Herring <robh+dt@xxxxxxxxxx>
> CC: Will Deacon <will.deacon@xxxxxxx>
> CC: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
> ---
> drivers/acpi/acpi_platform.c | 7 ++++++-
> drivers/acpi/glue.c | 5 +++--
> drivers/acpi/scan.c | 39 +++++++++++++++++++++++++++++++++++++++
> drivers/base/property.c | 8 ++++++--
> include/acpi/acpi_bus.h | 36 ++----------------------------------
> include/linux/acpi.h | 4 ++--
> 6 files changed, 58 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
> index 06a67d5..2261e85 100644
> --- a/drivers/acpi/acpi_platform.c
> +++ b/drivers/acpi/acpi_platform.c
> @@ -103,7 +103,12 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
> pdevinfo.res = resources;
> pdevinfo.num_res = count;
> pdevinfo.fwnode = acpi_fwnode_handle(adev);
> - pdevinfo.dma_mask = acpi_check_dma(adev, NULL) ? DMA_BIT_MASK(32) : 0;
> +
> + if (-1 != acpi_check_dma_coherency(adev))
> + pdevinfo.dma_mask = DMA_BIT_MASK(32);
> + else
> + pdevinfo.dma_mask = 0;
> +
> pdev = platform_device_register_full(&pdevinfo);
> if (IS_ERR(pdev))
> dev_err(&adev->dev, "platform device creation failed: %ld\n",
> 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?


>
> 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?


> arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
>
> acpi_physnode_link_name(physical_node_name, node_id);

Thanks,
Rafael

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