[U-Boot] [PATCH 08/22] dm: usb: Use device_chld_remove and _unbind to clean up usb devs on stop

[Hans de Goede]

On an usb stop instead of leaving orphan usb devices behind simply remove
them. This requires CONFIG_DM_DEVICE_REMOVE to be set, so only build
usb_stop() when that is set.

The result of this commit is best seen in the output of "dm tree" after
plugging out an usb hub with 2 devices plugges in and plugging in a keyb.
instead, before this commit the output would be:

 usb         [ + ]    `-- sunxi-musb
 usb_hub     [   ]        |-- usb_hub
 usb_mass_st [   ]        |   |-- usb_mass_storage
 usb_dev_gen [   ]        |   `-- generic_bus_0_dev_3
 usb_dev_gen [ + ]        `-- generic_bus_0_dev_1

Notice the non active usb_hub child and its 2 non active children. The
first child being non-active as in this example also causes usb_get_dev_index
to return NULL when probing the first child, which results in the usb kbd
code not binding to the keyboard.

With this commit in place the output after swapping and "usb reset" is:

 usb         [ + ]    `-- sunxi-musb
 usb_dev_gen [ + ]        `-- generic_bus_0_dev_1

As expected, and usb_get_dev_index works properly and the keyboard works.

After this commit usb_find_child() is only necessary for emulated usb
devices, so make its body #ifdef CONFIG_USB_EMUL.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 drivers/usb/host/usb-uclass.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/usb/host/usb-uclass.c b/drivers/usb/host/usb-uclass.c
index bce6cec..8f26e35 100644
--- a/drivers/usb/host/usb-uclass.c
+++ b/drivers/usb/host/usb-uclass.c
@@ -128,6 +128,7 @@ int usb_alloc_device(struct usb_device *udev)
 	return ops->alloc_device(bus, udev);
 }
 
+#ifdef CONFIG_DM_DEVICE_REMOVE
 int usb_stop(void)
 {
 	struct udevice *bus;
@@ -143,6 +144,12 @@ int usb_stop(void)
 	uc_priv = uc->priv;
 
 	uclass_foreach_dev(bus, uc) {
+		ret = device_chld_remove(bus);
+		if (ret && !err)
+			err = ret;
+		ret = device_chld_unbind(bus);
+		if (ret && !err)
+			err = ret;
 		ret = device_remove(bus);
 		if (ret && !err)
 			err = ret;
@@ -166,6 +173,7 @@ int usb_stop(void)
 
 	return err;
 }
+#endif
 
 static void usb_scan_bus(struct udevice *bus, bool recurse)
 {
@@ -491,6 +499,7 @@ static int usb_find_child(struct udevice *parent,
 			  struct usb_interface_descriptor *iface,
 			  struct udevice **devp)
 {
+#ifdef CONFIG_USB_EMUL /* Emulated devices are explictily bound */
 	struct udevice *dev;
 
 	*devp = NULL;
@@ -509,6 +518,7 @@ static int usb_find_child(struct udevice *parent,
 			return 0;
 		}
 	}
+#endif
 
 	return -ENOENT;
 }
-- 
2.4.3