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>
---
Changes for v2:
- Simplify the code per Alan's suggestion
drivers/usb/core/hub.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 4ee2a6a..acba56b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4383,6 +4383,7 @@ 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;
+ const char *driver_name;
/* root hub ports have a slightly longer reset period
* (from USB 2.0 spec, section 7.1.7.5)
@@ -4450,11 +4451,23 @@ 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->bus->controller->driver)
+ driver_name = udev->bus->controller->driver->name;
+ else
+ driver_name = udev->bus->sysdev->driver->name;
+
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_name);
/* Set up TT records, if needed */
if (hdev->tt) {
@@ -4586,7 +4599,7 @@ 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_name);
}
/* cope with hardware quirkiness:
--
2.7.4
--
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