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dm: usb: Copy over usb_device values from usb_scan_device() to final usb_device

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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 3 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

3) Calling usb_select_config() a second time fails on some usb-1 devices
plugged into usb-2 hubs, causing u-boot to not recognize these devices.

This commit fixes these 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.

*) Except for devices which are explictly instantiated through device-tree
rather then discovered through usb_scan_device() such as emulated usb devices
in the sandbox.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Hans de Goede 2015-05-05 11:54:32 +02:00 committed by Simon Glass
parent f78a5c0774
commit 7f1a07538f
2 changed files with 38 additions and 22 deletions
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43
drivers/usb/host/usb-uclass.c
View File

@ -533,11 +533,7 @@ 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) {
@ -597,17 +593,34 @@ int usb_child_pre_probe(struct udevice *dev)
struct usb_dev_platdata *plat = dev_get_parent_platdata(dev);
int ret;
udev->controller_dev = usb_get_bus(dev);
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);
if (plat->udev) {
/*
* 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);
/* And clear plat->udev as it will not be valid for long */
plat->udev = NULL;
udev->dev = dev;
} else {
/*
* This happens with devices which are explicitly bound
* instead of being discovered through usb_scan_device()
* such as sandbox emul devices.
*/
udev->dev = dev;
udev->controller_dev = usb_get_bus(dev);
udev->devnum = plat->devnum;
ret = usb_select_config(udev);
if (ret)
return ret;
/*
* udev did not go through usb_scan_device(), so we need to
* select the config and read the config descriptors.
*/
ret = usb_select_config(udev);
if (ret)
return ret;
}
return 0;
}

17
include/usb.h
View File

@ -571,20 +571,23 @@ struct usb_platdata {
* This is used by sandbox to provide emulation data also.
*
* @id: ID used to match this device
* @speed: Stores the speed associated with a USB device
* @devnum: Device address on the USB bus
* @slot_id: USB3 slot ID, which is separate from the device address
* @portnr: Port number of this device on its parent hub, numbered from 1
* (0 mean this device is the root hub)
* @udev: usb-uclass internal use only do NOT use
* @strings: List of descriptor strings (for sandbox emulation purposes)
* @desc_list: List of descriptors (for sandbox emulation purposes)
*/
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 */
/*
* This pointer is used to pass the usb_device used in usb_scan_device,
* to get the usb descriptors before the driver is known, to the
* actual udevice once the driver is known and the udevice is created.
* This will be NULL except during probe, do NOT use.
*
* This should eventually go away.
*/
struct usb_device *udev;
#ifdef CONFIG_SANDBOX
struct usb_string *strings;
/* NULL-terminated list of descriptor pointers */