[U-Boot] [RFC 1/4] dm: usb: Copy over usb_device values from usb_scan_device() to final usb_device

[Hans de Goede]

Currently we copy over a number of usb_device values stored in the on stack
struct usb_device probed in usb_scan_device() to the final driver-model managed
struct usb_device in usb_child_pre_probe() through usb_device_platdata, and
then call usb_select_config() to fill in the rest.

There are 2 problems with this approach:

1) It does not fill in enough fields before calling usb_select_config(),
specifically it does not fill in ep0's maxpacketsize causing a div by zero
exception in the ehci driver.

2) It unnecessarily redoes a number of usb requests making usb probing slower,
and potentially upsetting some devices.

This commit fixes both issues by removing the usb_select_config() call from
usb_child_pre_probe(), and instead of copying over things field by field
through usb_device_platdata, store a pointer to the in stack usb_device
(which is still valid when usb_child_pre_probe() gets called) and copy
over the entire struct.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
Changes in v2:
-Remove code setting controller_dev from usb_child_pre_probe as that is
 already done in usb_scan_device() and copied over with the rest
---
 drivers/usb/host/usb-uclass.c | 27 ++++++---------------------
 include/usb.h                 |  5 +----
 2 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/drivers/usb/host/usb-uclass.c b/drivers/usb/host/usb-uclass.c
index 714bc0e..95e371d 100644
--- a/drivers/usb/host/usb-uclass.c
+++ b/drivers/usb/host/usb-uclass.c
@@ -535,12 +535,7 @@ int usb_scan_device(struct udevice *parent, int port,
 	}
 	plat = dev_get_parent_platdata(dev);
 	debug("%s: Probing '%s', plat=%p\n", __func__, dev->name, plat);
-	plat->devnum = udev->devnum;
-	plat->speed = udev->speed;
-	plat->slot_id = udev->slot_id;
-	plat->portnr = port;
-	debug("** device '%s': stashing slot_id=%d\n", dev->name,
-	      plat->slot_id);
+	plat->udev = udev;
 	priv->next_addr++;
 	ret = device_probe(dev);
 	if (ret) {
@@ -599,25 +594,15 @@ int usb_get_bus(struct udevice *dev, struct udevice **busp)
 
 int usb_child_pre_probe(struct udevice *dev)
 {
-	struct udevice *bus;
 	struct usb_device *udev = dev_get_parentdata(dev);
 	struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
-	int ret;
 
-	ret = usb_get_bus(dev, &bus);
-	if (ret)
-		return ret;
-	udev->controller_dev = bus;
+	/*
+	 * Copy over all the values set in the on stack struct usb_device in
+	 * usb_scan_device() to our final struct usb_device for this dev.
+	 */
+	*udev = *(plat->udev);
 	udev->dev = dev;
-	udev->devnum = plat->devnum;
-	udev->slot_id = plat->slot_id;
-	udev->portnr = plat->portnr;
-	udev->speed = plat->speed;
-	debug("** device '%s': getting slot_id=%d\n", dev->name, plat->slot_id);
-
-	ret = usb_select_config(udev);
-	if (ret)
-		return ret;
 
 	return 0;
 }
diff --git a/include/usb.h b/include/usb.h
index 1984e8f..1b667ff 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -581,10 +581,7 @@ struct usb_platdata {
  */
 struct usb_dev_platdata {
 	struct usb_device_id id;
-	enum usb_device_speed speed;
-	int devnum;
-	int slot_id;
-	int portnr;	/* Hub port number, 1..n */
+	struct usb_device *udev;
 #ifdef CONFIG_SANDBOX
 	struct usb_string *strings;
 	/* NULL-terminated list of descriptor pointers */
-- 
2.3.6