From: Michael Brown <mcb30@ipxe.org>
Date: Mon, 7 Sep 2015 00:25:41 +0000 (+0100)
Subject: [efi] Allow efidev_parent() to traverse multiple device generations
X-Git-Tag: v1.20.1~701
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5cea7bdb2af44a5e6b652c302f2761dc8fa1048f;p=thirdparty%2Fipxe.git

[efi] Allow efidev_parent() to traverse multiple device generations

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/interface/efi/efi_driver.c b/src/interface/efi/efi_driver.c
index 2a59257b8..b59362c64 100644
--- a/src/interface/efi/efi_driver.c
+++ b/src/interface/efi/efi_driver.c
@@ -68,18 +68,16 @@ static struct efi_device * efidev_find ( EFI_HANDLE device ) {
  * @ret efidev		Parent EFI device, or NULL
  */
 struct efi_device * efidev_parent ( struct device *dev ) {
-	struct device *parent = dev->parent;
-	struct efi_device *efidev;
+	struct device *parent;
 
-	/* Check that parent exists and is an EFI device */
-	if ( ! parent )
-		return NULL;
-	if ( parent->desc.bus_type != BUS_TYPE_EFI )
-		return NULL;
+	/* Walk upwards until we find an EFI device */
+	while ( ( parent = dev->parent ) ) {
+		if ( parent->desc.bus_type == BUS_TYPE_EFI )
+			return container_of ( parent, struct efi_device, dev );
+		dev = parent;
+	}
 
-	/* Get containing EFI device */
-	efidev = container_of ( parent, struct efi_device, dev );
-	return efidev;
+	return NULL;
 }
 
 /**