From 9054fc6d57e80c27c0b0632966416144f2092c2b Mon Sep 17 00:00:00 2001
From: Sakari Ailus <sakari.ailus@linux.intel.com>
Date: Wed, 17 Nov 2021 20:07:34 +0200
Subject: [PATCH] ACPI: Get acpi_device's parent from the parent field
Git-commit: 9054fc6d57e80c27c0b0632966416144f2092c2b
Patch-mainline: v5.16-rc3
References: git-fixes
Printk modifier %pfw is used to print the full path of the device name.
This is obtained device by device until a device no longer has a parent.
On ACPI getting the parent fwnode is done by calling acpi_get_parent()
which tries to down() a semaphore. But local IRQs are now disabled in
vprintk_store() before the mutex is acquired. This is obviously a problem.
Luckily struct device, embedded in struct acpi_device, has a parent field
already. Use that field to get the parent instead of relying on
acpi_get_parent().
Fixes: 3bd32d6a2ee6 ("lib/vsprintf: Add %pfw conversion specifier for printing fwnode names")
Cc: 5.5+ <stable@vger.kernel.org> # 5.5+
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/acpi/property.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index e312ebaed8db..781e312f4534 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1090,15 +1090,10 @@ struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode)
/* All data nodes have parent pointer so just return that */
return to_acpi_data_node(fwnode)->parent;
} else if (is_acpi_device_node(fwnode)) {
- acpi_handle handle, parent_handle;
+ struct device *dev = to_acpi_device_node(fwnode)->dev.parent;
- handle = to_acpi_device_node(fwnode)->handle;
- if (ACPI_SUCCESS(acpi_get_parent(handle, &parent_handle))) {
- struct acpi_device *adev;
-
- if (!acpi_bus_get_device(parent_handle, &adev))
- return acpi_fwnode_handle(adev);
- }
+ if (dev)
+ return acpi_fwnode_handle(to_acpi_device(dev));
}
return NULL;
--
2.31.1