The controller driver may be NULL if the controller device
is the middle device between platform device and roothub.
This middle device may not need a device driver due to all
hardware control can be at platform device driver, this
platform device is usually a dual-role USB controller device.
The benefit of using this middle device is we can keep both
controller device's private data (known as struct usb_hcd)
for USB core use, and platform device's private data for
platform driver use.
Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
---
drivers/usb/core/hub.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 6d4d36d..96621fe 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4379,6 +4379,8 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
enum usb_device_speed oldspeed = udev->speed;
const char *speed;
int devnum = udev->devnum;
+ struct device_driver *driver = udev->bus->controller->driver;
+ struct device_driver *sysdev_driver = udev->bus->sysdev->driver;
/* root hub ports have a slightly longer reset period
* (from USB 2.0 spec, section 7.1.7.5)
@@ -4446,11 +4448,19 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
else
speed = usb_speed_string(udev->speed);
+ /*
+ * The controller driver may be NULL if the controller device
+ * is the middle device between platform device and roothub.
+ * This middle device may not need a device driver due to
+ * all hardware control can be at platform device driver, this
+ * platform device is usually a dual-role USB controller device.
+ */
if (udev->speed < USB_SPEED_SUPER)
dev_info(&udev->dev,
"%s %s USB device number %d using %s\n",
(udev->config) ? "reset" : "new", speed,
- devnum, udev->bus->controller->driver->name);
+ devnum, driver ? driver->name :
+ sysdev_driver->name);
/* Set up TT records, if needed */
if (hdev->tt) {
@@ -4582,7 +4592,7 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
"%s SuperSpeed%s USB device number %d using %s\n",
(udev->config) ? "reset" : "new",
(udev->speed == USB_SPEED_SUPER_PLUS) ? "Plus" : "",
- devnum, udev->bus->controller->driver->name);
+ devnum, driver ? driver->name : sysdev_driver->name);
}
/* cope with hardware quirkiness:
--
2.7.4
--
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