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ACPI: platform: Use acpi_bus_get_primary_device()

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The acpi_get_first_physical_node() usage in acpi_platform_fill_resource()
and acpi_create_platform_device() is generally unsafe because in theory
the device returned by it may be freed at any time [1].

It is also inefficient because acpi_get_first_physical_node() is called
multiple times for the same argument which can be avoided.

Address these issues by using acpi_bus_get_primary_device() instead of
acpi_get_first_physical_node() and adjusting the code to call it just
once at the beginning of and acpi_create_platform_device() and drop
the device reference acquired by it upon the return from that function.

Fixes: 3b95bd1605 ("ACPI: introduce a function to find the first physical device")
Fixes: a252d881c5 ("ACPI / platform: Pay attention to parent device's resources")
Link: https://sashiko.dev/#/patchset/12955541.O9o76ZdvQC%40rafael.j.wysocki [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/3436112.aeNJFYEL58@rafael.j.wysocki
This commit is contained in:
Rafael J. Wysocki
2026-08-10 13:38:08 +02:00
parent 72530e1f72
commit a9ba4dd2f1
1 changed files with 7 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/acpi/acpi_platform.c
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@@ -102,18 +102,15 @@ static unsigned int acpi_platform_adjust_resources(struct acpi_device *adev,
return count;
}
static void acpi_platform_fill_resource(struct acpi_device *adev,
const struct resource *src, struct resource *dest)
static void acpi_platform_fill_resource(struct device *parent,
const struct resource *src,
struct resource *dest)
{
struct device *parent;
*dest = *src;
/*
* If the device has parent we need to take its resources into
* account as well because this device might consume part of those.
*/
parent = acpi_get_first_physical_node(acpi_dev_parent(adev));
if (parent && dev_is_pci(parent))
dest->parent = pci_find_resource(to_pci_dev(parent), dest);
}
@@ -141,7 +138,8 @@ static unsigned int acpi_platform_resource_count(struct acpi_resource *ares, voi
struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
const struct property_entry *properties)
{
struct acpi_device *parent = acpi_dev_parent(adev);
struct acpi_device *p = acpi_dev_parent(adev);
struct device *parent __free(put_device) = acpi_bus_get_primary_device(p);
struct platform_device *pdev = NULL;
struct platform_device_info pdevinfo;
const struct acpi_device_id *match;
@@ -187,7 +185,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
rentry->res,
resources,
count);
acpi_platform_fill_resource(adev, rentry->res,
acpi_platform_fill_resource(parent, rentry->res,
&resources[count++]);
}
acpi_dev_free_resource_list(&resource_list);
@@ -200,7 +198,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
* attached to it, that physical device should be the parent of the
* platform device we are about to create.
*/
pdevinfo.parent = parent ? acpi_get_first_physical_node(parent) : NULL;
pdevinfo.parent = parent;
pdevinfo.name = dev_name(&adev->dev);
pdevinfo.id = PLATFORM_DEVID_NONE;
pdevinfo.res = resources;