From: Joerg Roedel <jroedel@xxxxxxx>
The function acpi_bus_attach() creates platform_devices if
this is specified by the firmware. But in acpi_bus_trim()
these devices are not removed, leaving a dangling reference
to the parent device.
In the case of a PCI root-bus, this results in the
host_bridge device not being released on hot-remove.
Fix it by scanning the list of platform_devices for devices
to be removed with the bus.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
drivers/acpi/scan.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 1926918..b07518b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -13,6 +13,7 @@
#include <linux/dmi.h>
#include <linux/nls.h>
#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
#include <asm/pgtable.h>
@@ -1928,6 +1929,25 @@ int acpi_bus_scan(acpi_handle handle)
EXPORT_SYMBOL(acpi_bus_scan);
/**
+ * acpi_bus_trim_platform_device - Check and remove a platform device
+ * from a bus
+ * @dev: Platform device to check
+ * @data: pointer to the acpi_device to check dev against
+ *
+ * Checks whether the platform_device dev belongs to the acpi_device
+ * data and unregisters dev if it matches.
+ */
+static int acpi_bus_trim_platform_device(struct device *dev, void *data)
+{
+ struct acpi_device *adev = data;
+
+ if (dev->fwnode == acpi_fwnode_handle(adev))
+ platform_device_unregister(to_platform_device(dev));
+
+ return 0;
+}
+
+/**
* acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
* @adev: Root of the ACPI namespace scope to walk.
*
@@ -1950,6 +1970,12 @@ void acpi_bus_trim(struct acpi_device *adev)
} else {
device_release_driver(&adev->dev);
}
+
+ /* Remove platform devices from the bus */
+ if (adev->pnp.type.platform_id)
+ bus_for_each_dev(&platform_bus_type, NULL, adev,
+ acpi_bus_trim_platform_device);
+
/*
* Most likely, the device is going away, so put it into D3cold before
* that.
--
1.9.1
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