[U-Boot] [PATCH 1/5] dm: core: Handle recursive unbinding of uclass devices

Simon Glass sjg at chromium.org
Sun Apr 19 15:20:58 CEST 2015


Since a device can have children in the same uclass as itself, we need
to handle unbinding carefully: we must allow that unbinding a device in a
uclass may cause another device in the same uclass to be unbound.

Adjust the code to cope.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 drivers/core/uclass.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
index 98c15e5..45fcd08 100644
--- a/drivers/core/uclass.c
+++ b/drivers/core/uclass.c
@@ -99,10 +99,18 @@ fail_mem:
 int uclass_destroy(struct uclass *uc)
 {
 	struct uclass_driver *uc_drv;
-	struct udevice *dev, *tmp;
+	struct udevice *dev;
 	int ret;
 
-	list_for_each_entry_safe(dev, tmp, &uc->dev_head, uclass_node) {
+	/*
+	 * We cannot use list_for_each_entry_safe() here. If a device in this
+	 * uclass has a child device also in this uclass, it will be also be
+	 * unbound (by the recursion in the call to device_unbind() below).
+	 * We can loop until the list is empty.
+	 */
+	while (!list_empty(&uc->dev_head)) {
+		dev = list_first_entry(&uc->dev_head, struct udevice,
+				       uclass_node);
 		ret = device_remove(dev);
 		if (ret)
 			return ret;
-- 
2.2.0.rc0.207.ga3a616c



More information about the U-Boot mailing list