From 1bb90cf0462c9a07cb428e9dd9665041fe7f9e18 Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Wed, 19 Jul 2017 14:40:53 +0800 Subject: [PATCH] usb: core: hub: controller driver name may be NULL 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 Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- 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 6e6797d..7e36700 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4342,6 +4342,7 @@ 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) @@ -4409,11 +4410,23 @@ 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) { @@ -4545,7 +4558,7 @@ 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